This is a very small light sensor. A photo resistor (also known as a photodector, or photocell) changes resistance depending on the amount of light it is exposed to.
900 MHz Rubber Duck Antenna - Male Type F
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. Customized version of item TP-200-001.