This is a 9V battery clip typically used for our wireless cameras. The ID is 2.1mm, the OD is 5.5mm. Center positive.
9V Battery Snap with 12" Leads
The GPS 18x is an OEM, high-sensitivity GPS sensor for use in automotive, fleet vehicle, and electronics applications that require a small, highly accurate GPS receiver.
The HD2 tracked platform is a large, heavy duty tracked robot with the power to pull a truck and climb stairs. A wealth of internal space allows for batteries, controls and an optional computer.