Easily attachable to a belt backpack strap or bag the peak design lens kit adapter allows you to have up to two spare lenses near to hand at all times and change between them quickly and securely no more fumbling in your bag for the right glass as the lens kit freely swivels to allow you access each one at a moments notice the 4 direction lock keeps the lenses held in place when not in use while the robust glass reinforced nylon build is light but strong