These are high quality sealed Single Pole - Double Through (SPDT) relays. This relay's coil is rated for 12V. These are rated up to 240VAC or 28VDC at 10A.
Powered by the ULN2003 high current driver, this module gives you easy control of up to 7 relays using TTL logic from an Arduino, Beagle Bone, or Raspberry Pi. 5V, 12V, and 24V relay options.
Use these roll pins to fix sprockets to a shaft and keep them locked in place.
This is a small tracked robot equipped with 42mm motors, a motor controller, and Spektrum remote control. Don't let its size fool you. This is a rugged little robot.