diff --git a/lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/coins/Coins.java b/lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/coins/Coins.java
new file mode 100644
index 000000000..59aaabd00
--- /dev/null
+++ b/lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/coins/Coins.java
@@ -0,0 +1,86 @@
+package com.codedifferently.lesson16.coins;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Coins {
+
+  public enum CoinType {
+    PENNY,
+    NICKEL,
+    DIME,
+    QUARTER
+  }
+
+  private final CoinType coinType;
+  private final int coinValue;
+  private final boolean coinIsRare;
+  private final double coinGramWeight;
+  private final int coinAge;
+  private final List<String> material;
+  private static final List<Coins> coinCollection = new ArrayList<>();
+
+  // constructor
+  public Coins(
+      CoinType coinType,
+      int coinValue,
+      Boolean coinIsRare,
+      Double coinGramWeight,
+      int coinAge,
+      List<String> material) {
+    this.coinType = coinType;
+    this.coinValue = coinValue;
+    this.coinIsRare = coinIsRare;
+    this.coinGramWeight = coinGramWeight;
+    this.coinAge = coinAge;
+    this.material = material;
+  }
+
+  // Getters and Setters
+  public CoinType getCoinType() {
+    return coinType;
+  }
+
+  public int getCoinValue() {
+    return coinValue;
+  }
+
+  public boolean isCoinRare() {
+    return coinIsRare;
+  }
+
+  public double getCoinGramWeight() {
+    return coinGramWeight;
+  }
+
+  public int getCoinAge() {
+    return coinAge;
+  }
+
+  public List<String> getMaterial() {
+    List<String> materialsList = new ArrayList<>();
+    for (String mat : material) {
+      materialsList.add(mat);
+    }
+    return materialsList;
+  }
+
+  public static int convertNickelsToDimes(int totalNickels) {
+    if (totalNickels < 1) {
+      throw new IllegalArgumentException("you do not have enough nickles");
+    }
+    return totalNickels / 2;
+  }
+
+  public static List<Coins> setCoinCollection() {
+    Coins penny = new Coins(Coins.CoinType.PENNY, 1, true, 2.5, 1977, List.of("zinc", "copper"));
+    Coins nickel =
+        new Coins(Coins.CoinType.NICKEL, 5, true, 5.0, 1953, List.of("nickel", "copper"));
+    Coins dime = new Coins(CoinType.DIME, 10, true, 10.0, 1957, List.of("nickel", "copper"));
+
+    coinCollection.add(penny);
+    coinCollection.add(nickel);
+    coinCollection.add(dime);
+    return coinCollection;
+  }
+}
diff --git a/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/coins/CoinsTest.java b/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/coins/CoinsTest.java
new file mode 100644
index 000000000..5ac862f8f
--- /dev/null
+++ b/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/coins/CoinsTest.java
@@ -0,0 +1,91 @@
+package com.codedifferently.lesson16.coins;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+import com.codedifferently.lesson16.coins.Coins.CoinType;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class CoinTest {
+
+  @Test
+  void testCheckCoinInPocket() {
+    // arrange
+    Coins coin = new Coins(CoinType.NICKEL, 5, false, 5.0, 1953, List.of("nickel", "copper"));
+    // act action
+    Coins.CoinType actualCoin = coin.getCoinType();
+    int coinValue = coin.getCoinValue();
+    boolean coinRarity = coin.isCoinRare();
+
+    // assert
+    assertEquals(CoinType.NICKEL, actualCoin);
+    assertEquals(5, coinValue);
+    assertFalse(coinRarity);
+  }
+
+  @Test
+  void testWeighCoins() {
+    // arrange
+    Coins coin = new Coins(CoinType.NICKEL, 5, false, 5.0, 1953, List.of("nickel", "copper"));
+    double expectedWeight = 5.0;
+    // act
+    double coinWeight = coin.getCoinGramWeight();
+    // assert
+    assertEquals(expectedWeight, coinWeight);
+  }
+
+  @Test
+  void testConvertCoins() {
+    // arrange
+    List<Coins> coinCollection = new ArrayList<>();
+    coinCollection.add(new Coins(CoinType.NICKEL, 5, false, 5.0, 1953, List.of()));
+    coinCollection.add(new Coins(CoinType.NICKEL, 5, false, 5.0, 1953, List.of()));
+    // act
+    int totalNickles = coinCollection.size();
+    int dimes = Coins.convertNickelsToDimes(totalNickles);
+    // assert
+    assertEquals(1, dimes);
+  }
+
+  @Test
+  void testCoinCollection() {
+    // arrange
+    List<Coins> coinCollection = Coins.setCoinCollection();
+
+    assertEquals(3, coinCollection.size());
+  }
+
+  @Test
+  void testGetAgeCoin() {
+    // arrange
+    Coins dime = new Coins(CoinType.DIME, 10, true, 10.0, 1957, List.of("nickel", "copper"));
+    // Act
+    int age = dime.getCoinAge();
+    // Assert
+    assertEquals(1957, age);
+  }
+
+  @Test
+  void testGetMaterialComposition() {
+    // arrange
+    Coins penny = new Coins(CoinType.PENNY, 1, true, 2.5, 1977, List.of("zinc", "copper"));
+    // act
+    List<String> materialComposition = penny.getMaterial();
+    // assert
+    assertThat(materialComposition).containsExactly("zinc", "copper");
+  }
+
+  @Test
+  void testCannotConvert() {
+    assertThatThrownBy(
+            () -> {
+              Coins.convertNickelsToDimes(0);
+            })
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessageContaining("you do not have enough nickles");
+  }
+}