The CapBuckle Lens Cap Holder for 37/40.5/43/46mm Lens Caps provides you with a secure and out-of-the-way system to hold your lens cap. The design copies the front of your lens and is sized to hold the cap. The CapBuckle threads to your shoulder strap eliminating the need for any dangling cap holder that might swing in front of your lens. Just squeeze the locking mechanism on your lens cap and put it in the Cap Buckle where it remains locked on the camera's strap. Each Cap Buckle holds three sizes of lens caps on opposing sides of the holder. Multiple Cap Buckles can be attached to your camera strap to accommodate various size lens caps. This is a lightweight, durable way to make sure your lens cap is safe and readily accessible.