The retainer/leash to hold the cap is broken on my old boat. iboats should update their photo to show that the cap is just a cap. Can't tell since the photo shows the whole assembly with a leash for the cap. When your new cap arrives you still won't have anything to keep it from dropping in the lake but you will have an extra cap for when it does! In my boat, getting to the other side of the gas cap to remove the fuel line and install whole device would require me to disassemble quite a bit of interior (done it before, don't want to do it again for just a gas cap) so I will just be careful when taking off the cap - and I have a spare.