Size Details: Our chin strap swim cap is made of approximately 2.5mm/0.1 inch thick material that conforms to the curves of your head and face. This ensures a comfortable wearing experience, so you can enjoy a wonderful diving time underwater. Durable: This neoprene swim cap is made of elastic neoprene and nylon, which is reliable and retains its shape. It is stretchy and comfortable, providing warmth and protection for your sensitive head. Your Ideal Assistant: This neoprene swim cap keeps your hair neat while diving, snorkeling, swimming or kayaking. You don't have to worry about blowing or tangled hair, saving you time and energy. Practical Strap Design: This surf cap has a flat seam design, which is comfortable to wear and reduces drag in the water, so you stay warm underwater. The chin strap design keeps the swim cap stable and you can adjust its tightness. Applicable occasions: This swimming cap is suitable for swimming, diving, snorkeling, kayaking, fishing, surfing, sailing, canoeing, etc. The swimming cap is not completely waterproof and you also need to use it in combination with other diving equipment.