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
This is a direct drive 4WD base Programmable robot kit that uses Nexus mecanum wheels and hubs. This robot platform is meant for indoor robotics. It can vector in any direction. Prebuilt version of TP-095-004.
This is the chain and sprocket kit for the IG42-DB4 robot platform. It includes 10 tooth and 15 tooth sprockets, 6 feet of chain, and 4 connecting links.