This is the phone plug for Lego NXT/EV3. 

This is a driver board for stepper motor with chipset ULN2003. There are four LEDs on the board to show A,B,C,D four-phases working status. It has a 2.54mm spacing header for easy connection.  The...

This is a code disk for speed encoder. It has 20 grids. The diameter of this code disk is 23mm. It has a D shape hole diameter 4mm.

This is a breakout of U-shape motor speed measurement.   Download: Tutorial

This is a handy potentiometer breakout that can be used to adjust signal level in robotics.

LinkSprite infrared roadblock sensor uses an integrated infrared transceiver.  74LS00 is used to construct a resonator. Adjust the potentiometer can adjust the frequency of the infrared light to be...

Flame sensor is only sensitive to the light in the frequency band of infrared and ultrviolet. This breakout board has 3 pins: sensor output signal, power, and ground. The sensor output signal is an...

Toy Tires - Off Road Off-road Tires: 2.0" Diameter Comes in a pair

Diameter: 10.0mm Thickness: 3.4mm Voltage: DC 3.0V Loadless speed: 12000rpm This itty-bitty, shaftless vibratory motor is perfect for non-audible indicators. Use in any number of applications...

This is a fixture for servos of webcam used for robotics. The picute shows a complete set including the camera.

This is a bump detector that can detect a crash event. 

Omni-directional supporting metal ball wheel for the rear wheel of robot. Spec:   Fixture hole diameter: 4mm Distance between centers of fixture holes: 40 mm Height: 20mm Wheel ball diameter:...