Yves Saint Laurent (YSL) is a renowned luxury fashion brand known for its elegant and sophisticated designs, including their iconic bags. Yves Saint Laurent bags often showcase a blend of timeless aesthetics, high-quality materials, and meticulous craftsmanship. While I don't have real-time information on specific bag models released after September 2021, I can provide you with a general overview of the brand's bag offerings up to that point:

1. YSL Envelope Bag: This is one of the most iconic designs from the brand, featuring a flap-front envelope shape with the interlocking YSL logo as a prominent clasp. It's available in various sizes, materials, and colors, making it a versatile option suitable for both casual and formal occasions.

2. YSL Sac de Jour: This bag is characterized by its structured silhouette, accordion sides, and top handles. It often comes in smooth or grained leather and offers a polished and refined look. It's perfect for a professional or chic ensemble.

3. YSL Kate Bag: The Kate bag is recognized by its rectangular shape, tassel detail, and a YSL logo prominently positioned on the front flap. It's available in different sizes and materials, making it suitable for evenings out or special events.

4. YSL Loulou Bag: This bag features a quilted design, often crafted from soft, luxurious leather. It has a Y-shaped quilting pattern and a YSL logo on the front flap. The Loulou bag is known for its versatility and comfort, making it a popular choice for everyday use.

5. YSL College Bag: The College bag showcases a mix of textures and colors, often combining leather and suede. It features a chevron quilting pattern and a prominent YSL logo. The chain strap adds a touch of elegance and edge to the design.

6. YSL Cassandra Bag: This bag is named after the iconic YSL logo, known as the Cassandra logo. The bag features a structured shape with the logo as a distinctive clasp. It's available in various sizes and styles, offering a contemporary and sophisticated look.

7. YSL Niki Bag: The Niki bag is recognized for its slouchy and relaxed silhouette. It often features crinkled leather, a fold-over flap, and a metal YSL logo with a vintage-inspired aesthetic.