This part works with the PEQ Mount Base (sold separately on my shop http://shpws.me/J4ux). The cap locks onto the base covering the Mobius cameras and giving the mount the appearance of a PEQ box typically found on modern firearms and very popular with airsofters. The cap is easy to snap on and remove and has been drop tested (accidentally) and can withstand a rough hit to the ground (not recommended). The cap works in conjunction with the PEQ Mount Base and covers the two Mobius cameras while still allowing access to all the important functions of the camera. The two power buttons are exposed to allow for quick record start and stop, it is recommended that the Mobius cameras be configured for one button record. Additional openings allow for the heat sinks to be exposed as well as the record light indicator on top and back of the mount while covering the forward facing light to further reduce the signature of the mount and cameras.