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
Use these roll pins to fix sprockets to a shaft and keep them locked in place.
The MGS1600GY is a sensor capable of detecting and reporting the position of a magnetic field (typically magnetic tape on the floor) along its horizontal axis. Includes a built in Gyro. Replaces MGS1600 TS-072-000