1. Simple mechanical structure, very easy to install. 2. Four deceleration DC motors are used for flexible turning and good directionality. Four-wheel drive, full of horsepower. The chassis is and stable, very easy to expand 3. Double-layer structure: easy to expand Color: Yellow Material: plastic Product Description Type: 4WD smart car kit Model: smart car chassis Uses: Suitable for bluetooth remote control car accessories Special service: with speed encoder and battery box Series: smart car Package Contents: 1 Assembled Electronic Auto Parts 1 x With Chinese and English instructions Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.