diff --git a/Project.toml b/Project.toml
index fb66182..3fba43c 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "GradedArrays"
 uuid = "bc96ca6e-b7c8-4bb6-888e-c93f838762c2"
 authors = ["ITensor developers <support@itensor.org> and contributors"]
-version = "0.5.1"
+version = "0.5.2"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
diff --git a/src/GradedArrays.jl b/src/GradedArrays.jl
index 477f22d..236168a 100644
--- a/src/GradedArrays.jl
+++ b/src/GradedArrays.jl
@@ -2,12 +2,12 @@ module GradedArrays
 
 include("gradedunitrange_interface.jl")
 
-include("abstractsector.jl")
+include("sectorrange.jl")
 include("sectorunitrange.jl")
 include("gradedunitrange.jl")
 
 include("namedtuple_operations.jl")
-include("sector_product.jl")
+include("sectorproduct.jl")
 
 include("fusion.jl")
 include("gradedarray.jl")
diff --git a/src/gradedunitrange.jl b/src/gradedunitrange.jl
index 97d709f..f274017 100644
--- a/src/gradedunitrange.jl
+++ b/src/gradedunitrange.jl
@@ -27,6 +27,8 @@ using Compat: allequal
 abstract type AbstractGradedUnitRange{T, BlockLasts} <:
 AbstractBlockedUnitRange{T, BlockLasts} end
 
+to_gradedrange(r::AbstractGradedUnitRange) = r
+
 struct GradedUnitRange{T, SUR <: SectorOneTo{T}, BR <: AbstractUnitRange{T}, BlockLasts} <:
     AbstractGradedUnitRange{T, BlockLasts}
     eachblockaxis::Vector{SUR}
diff --git a/src/sector_product.jl b/src/sectorproduct.jl
similarity index 95%
rename from src/sector_product.jl
rename to src/sectorproduct.jl
index 3aa48cb..418392d 100644
--- a/src/sector_product.jl
+++ b/src/sectorproduct.jl
@@ -21,15 +21,12 @@ SectorProduct(c::SectorProduct) = _SectorProduct(arguments(c))
 SectorProduct(c::SectorRange...) = _SectorProduct(map(label, c))
 # SectorProduct(::TKS.Trivial) = _SectorProduct((;))  # empty tuple
 
-arguments(s::SectorProduct) = s.arguments
+arguments(s::SectorProduct) = getfield(s, :arguments)
 arguments_type(::Type{SectorProduct{T}}) where {T} = T
 
-function arguments(r::SectorProductRange{T}) where {T <: SectorProduct{<:Tuple}}
+function arguments(r::SectorProductRange)
     return map(SectorRange, arguments(label(r)))
 end
-function arguments(r::SectorProductRange{T}) where {T <: SectorProduct{<:NamedTuple}}
-    return NamedTuple(k => SectorRange(v) for (k, v) in pairs(arguments(label(r))))
-end
 
 function to_sector(nt::NamedTuple{<:Any, T}) where {T <: Tuple{Vararg{TKS.Sector}}}
     return SectorRange(SectorProduct(nt))
@@ -141,14 +138,13 @@ function Base.isless(s1::SectorProductRange, s2::SectorProductRange)
     return arguments(s1′) < arguments(s2′)
 end
 
-function Base.show(io::IO, r::SectorRange{<:SectorProduct})
-    s = label(r)
-    (length(arguments(s)) < 2) && print(io, "sector")
+function Base.show(io::IO, r::SectorProductRange)
+    (length(arguments(r)) < 2) && print(io, "sector")
     print(io, "(")
     symbol = ""
-    for p in pairs(arguments(s))
+    for (k, v) in pairs(arguments(r))
         print(io, symbol)
-        sector_show(io, p[1], SectorRange(p[2]))
+        sector_show(io, k, v)
         symbol = " × "
     end
     return print(io, ")")
@@ -177,6 +173,9 @@ const sectorproduct = ×
 ×(c1::SectorRange, c2::SectorRange) = SectorRange(×(label(c1), label(c2)))
 ×(c1::TKS.Sector, c2::TKS.Sector) = ×(SectorProduct(c1), SectorProduct(c2))
 
+# n-arg implemented as a left fold.
+×(r1, r2, r3, r_rest...) = ×(×(r1, r2), r3, r_rest...)
+
 function ×(p1::SectorProduct{<:Tuple}, p2::SectorProduct{<:Tuple})
     return SectorProduct(arguments(p1)..., arguments(p2)...)
 end
diff --git a/src/abstractsector.jl b/src/sectorrange.jl
similarity index 98%
rename from src/abstractsector.jl
rename to src/sectorrange.jl
index ef91251..4678179 100644
--- a/src/abstractsector.jl
+++ b/src/sectorrange.jl
@@ -68,7 +68,7 @@ function sector_label(c::TKS.Sector)
 end
 
 quantum_dimension(g::AbstractUnitRange) = length(g)
-quantum_dimension(r::SectorRange) = quantum_dimension(label(r))
+quantum_dimension(r::SectorRange) = TKS.dim(label(r))
 quantum_dimension(s::TKS.Sector) = TKS.dim(s)
 
 to_sector(x::TKS.Sector) = SectorRange(x)
@@ -190,6 +190,7 @@ function sector_label(c::TKS.CU1Irrep)
         c.j
     end
 end
+zero_odd(::Type{O2}) = O2(-1)
 
 const SU2 = SectorRange{TKS.SU2Irrep}
 sector_label(c::TKS.SU2Irrep) = c.j
diff --git a/test/test_symmetrysectors_fusion_rules.jl b/test/test_fusion_rule.jl
similarity index 100%
rename from test/test_symmetrysectors_fusion_rules.jl
rename to test/test_fusion_rule.jl
diff --git a/test/test_gradedunitrange.jl b/test/test_gradedunitrange.jl
index 2c60fdd..c6f4680 100644
--- a/test/test_gradedunitrange.jl
+++ b/test/test_gradedunitrange.jl
@@ -34,7 +34,8 @@ using GradedArrays:
     sector_type,
     sectors,
     sectorrange,
-    space_isequal
+    space_isequal,
+    to_gradedrange
 using Test: @test, @test_throws, @testset
 
 @testset "GradedUnitRanges basics" begin
@@ -43,11 +44,12 @@ using Test: @test, @test_throws, @testset
     g1 = gradedrange(["x" => 2, "y" => 3, "z" => 2])
     @test g1 isa GradedOneTo
     @test !isdual(g1)
+    @test to_gradedrange(g1) ≡ g1
 
     # Base.Slice
-    @test axes(Base.Slice(g1)) === (g1,)
-    @test Base.axes1(Base.Slice(g1)) === g1
-    @test Base.unsafe_indices(Base.Slice(g1)) === (g1,)
+    @test axes(Base.Slice(g1)) ≡ (g1,)
+    @test Base.axes1(Base.Slice(g1)) ≡ g1
+    @test Base.unsafe_indices(Base.Slice(g1)) ≡ (g1,)
 
     g2 = gradedrange(1, ["x" => 2, "y" => 3, "z" => 2])
     @test !(g2 isa GradedOneTo)
@@ -58,13 +60,13 @@ using Test: @test, @test_throws, @testset
     @test isdual(g1d)
 
     # Base.Slice
-    @test axes(Base.Slice(g1d)) === (g1d,)
-    @test Base.axes1(Base.Slice(g1d)) === g1d
-    @test Base.unsafe_indices(Base.Slice(g1d)) === (g1d,)
+    @test axes(Base.Slice(g1d)) ≡ (g1d,)
+    @test Base.axes1(Base.Slice(g1d)) ≡ g1d
+    @test Base.unsafe_indices(Base.Slice(g1d)) ≡ (g1d,)
 
     for g in (g1, g2, g1d)
         @test g isa GradedUnitRange
-        @test sector_type(g) === String
+        @test sector_type(g) ≡ String
         @test blockisequal(g, b0)
         @test space_isequal(g, g)
         @test space_isequal(copy(g), g)
@@ -138,7 +140,7 @@ using Test: @test, @test_throws, @testset
         @test a isa SectorUnitRange
         @test space_isequal(a, sectorrange("x" => 2, isdual(g)))
         @test space_isequal(g, g[:])
-        @test typeof(g[:]) === typeof(g)
+        @test typeof(g[:]) ≡ typeof(g)
 
         a = g[Block(2)[2:3]]
         @test a isa SectorUnitRange
@@ -276,7 +278,7 @@ end
     @test space_isequal(g[Block(1)], sectorrange(SU2(0), 2))
     @test space_isequal(g[Block(2)], sectorrange(SU2(1), 3:8))
 
-    @test sector_type(g) === SU2
+    @test sector_type(g) ≡ SU2
     @test space_isequal(g, g)
     @test g == 1:8
     @test space_isequal(dual(g), gradedrange([SU2(0) => 2, SU2(1) => 2]; isdual = true))
@@ -306,7 +308,7 @@ end
     @test a isa SectorUnitRange
     @test space_isequal(a, sectorrange(SU2(0) => 2))
     @test space_isequal(g, g[:])
-    @test typeof(g[:]) === typeof(g)
+    @test typeof(g[:]) ≡ typeof(g)
 
     a = g[Block(2)[2:3]]
     @test a isa UnitRange
diff --git a/test/test_symmetrysectors_sector_product.jl b/test/test_sectorproduct.jl
similarity index 99%
rename from test/test_symmetrysectors_sector_product.jl
rename to test/test_sectorproduct.jl
index 3726f0c..5070262 100644
--- a/test/test_symmetrysectors_sector_product.jl
+++ b/test/test_sectorproduct.jl
@@ -41,6 +41,8 @@ import TensorKitSectors as TKS
         @test (@constinferred trivial(s)) == SectorProduct(TKS.U1Irrep(0), TKS.U1Irrep(0))
 
         s = U1(1) × SU2(1 // 2) × U1(3)
+        @test s ≡ sectorproduct(U1(1), SU2(1 // 2), U1(3))
+        @test s ≡ ×(U1(1), SU2(1 // 2), U1(3))
         @test length(arguments(s)) == 3
         @test (@constinferred quantum_dimension(s)) == 2
         @test (@constinferred dual(s)) == U1(-1) × SU2(1 // 2) × U1(-3)
diff --git a/test/test_symmetrysectors_simple_sectors.jl b/test/test_sectors.jl
similarity index 99%
rename from test/test_symmetrysectors_simple_sectors.jl
rename to test/test_sectors.jl
index 2541fdb..304c658 100644
--- a/test/test_symmetrysectors_simple_sectors.jl
+++ b/test/test_sectors.jl
@@ -12,7 +12,8 @@ using GradedArrays:
     modulus,
     quantum_dimension,
     sector_type,
-    trivial
+    trivial,
+    zero_odd
 using SUNRepresentations: SUNRepresentations
 using Test: @test, @test_throws, @testset
 using TestExtras: @constinferred
@@ -100,6 +101,7 @@ fundamental(::Type{SU{N}}) where {N} = SU{N}((1, zeros(Int, N - 2)...))
 
         @test trivial(O2) == s0e
         @test istrivial(s0e)
+        @test zero_odd(O2) == s0o
 
         @test (@constinferred quantum_dimension(s0e)) == 1
         @test (@constinferred quantum_dimension(s0o)) == 1
diff --git a/test/test_show.jl b/test/test_show.jl
index 15ac565..620a1b7 100644
--- a/test/test_show.jl
+++ b/test/test_show.jl
@@ -12,7 +12,8 @@ show_non_namespaced(x) = sprint(show, x)
 @testset "show SymmetrySector" begin
     q1 = U1(1)
     @test show_namespaced(q1) == "U1(1)"
-    @test show_non_namespaced(q1) == "GradedArrays.U1(1)"
+    @test show_non_namespaced(q1) == "GradedArrays.U1(1)" ||
+        show_non_namespaced(q1) == "U1(1)"
 
     s0e = O2(0)
     s0o = O2(-1)