diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index a337ba4..5d22176 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -2,12 +2,13 @@
 
 ## Summary
 
-This is the initial release, extracted from the [SDK v1.0.0rc601](https://github.com/frequenz-floss/frequenz-sdk-python/releases/tag/v1.0.0-rc601).
+This first stable release of `frequenz-quantities`!
+
+The code is based on the quantities code in the [`frequenz-sdk` v1.0.0rc601](https://github.com/frequenz-floss/frequenz-sdk-python/releases/tag/v1.0.0-rc601) but with some new features and improvements.
 
 ## New Features
 
 - Added support for `__round__` (`round(quantity)`), `__pos__` (`+quantity`) and `__mod__` (`quantity % quantity`) operators.
 - Add `ReactivePower` quantity.
 - Add `ApparentPower` quantity.
-- Add an **experimental** marshmallow module available when adding `[marshmallow]` to the requirements.
-   * Add a QuantitySchema supporting string/float based serialization and deserialization of quantities.
+- Add an **experimental** marshmallow module available when adding `[marshmallow]` to the requirements. This module provides `marshmallow` fields for quantities and a `QuantitySchema` to use as a base schema that supports loading and dumping quantities.