ZK‎-4 4WD DIY Double Smart Car Chassis Kit with Speed Encoder Battery Box Motor   Main Features‎:‎ This Motor Smart Car Kit is a best Robot learning tutorial Motor power supply is 3V‎-12V All the parameter above is tested without load This smart car has functions include tracing‎,‎ obstacle avoidance‎,‎ distance testing‎,‎ speed testing‎,‎ wireless remote‎,‎ etc‎.‎ This is a complete motor smart car kit‎,‎ all you need to do is to finish it by starting from one part Gear motor deceleration indicator Chassis made from acrylic material With installation holes‎,‎ easy to use Great for DIY project   Features‎:‎ Educational   Package weight‎:‎ 0.610 kg Product Size ‎(‎L x W x H‎)‎ ‎:‎ 25.5 x 15x 6.5 cm / 10.0 x 5.9 x 2.6 inches Package Size ‎(‎L x W x H‎)‎ ‎:‎ 27.5 x 17 x 5 cm Package Contents‎:‎ 2 x Smart car chassis‎,‎ 4 x Motor wheels‎,‎ 4 x Speed measuring code discs‎,‎ 8 x Fasteners‎,‎ 1 x Installation drawing‎,‎ 1 x Power supply box‎,‎ 1 x Screws pack