diff --git a/Java Sets/src/ProductCatalogue.java b/Java Sets/src/ProductCatalogue.java
new file mode 100644
index 0000000..9e55948
--- /dev/null
+++ b/Java Sets/src/ProductCatalogue.java	
@@ -0,0 +1,20 @@
+import common.Product;
+import common.Supplier;
+
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+
+public class ProductCatalogue implements Iterable<Product> {
+    private final Set<Product> products = new HashSet<>();
+
+    public void addSupplier(final Supplier supplier) {
+
+        products.addAll(supplier.getProducts());
+    }
+
+    @Override
+    public Iterator<Product> iterator() {
+        return products.iterator();
+    }
+}
diff --git a/Java Sets/src/WeightAwareProductCatalogue.java b/Java Sets/src/WeightAwareProductCatalogue.java
new file mode 100644
index 0000000..79bc8ed
--- /dev/null
+++ b/Java Sets/src/WeightAwareProductCatalogue.java	
@@ -0,0 +1,28 @@
+import common.Product;
+import common.Supplier;
+
+import java.util.Iterator;
+import java.util.NavigableSet;
+import java.util.Set;
+import java.util.TreeSet;
+
+public class WeightAwareProductCatalogue implements Iterable<Product> {
+    private final NavigableSet<Product> products =
+            new TreeSet<>(Product.BY_WEIGHT);
+
+    public void addSupplier(final Supplier supplier) {
+
+        products.addAll(supplier.getProducts());
+    }
+
+    public Set<Product> findLighterProducts(final Product product) {
+
+        return products.headSet(product, false);
+    }
+
+    @Override
+    public Iterator<Product> iterator() {
+
+        return products.iterator();
+    }
+}