1. Keeps the motor cooler and improves motor operating efficiency. 2. Compatible with most / / RC car electric motors. 3. Made of high grade aluminum alloy material, and environmentally friendly. 4. Simple and easy to install. 5. Suitable for 540/550 motors. and high quality Color: Random Color(Random color, don't accept the specified color.) Material: aluminum alloy size: L x W x H=47 x 36 x 32mm, radiator arc diameter 36mm Package Contents: 3 x Motor Heat Sink for RC car 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.