Standard vacuum straight with KF25 flanges at each end.

Pololu

Step-down "buck" regulator for reducing input voltages as high as 36 volts down to 5v. Current output 500 mA, efficiency of around 80-93%. Features over temperature and over current shutdown. Not reverse voltage protected.Size: 0.5″ × 0.4″ × 0.1″ (13 mm × 10 mm × 3 mm)

Pololu

Dual 30 amp motor controller with thermal protection.

Sparkfun

None Provided

Pololu

Pololu QTR Sensor

Pololu

Pololu 38 kHz IR Sensor