The 540 55T crawler brush motor is made of metal material, which is firm and durable. Suitable for 1:10 remote control car, fit for HSP, for SCX10. Low internal resistance, strong resistant current capability, excellent hest dissipation. Lines are welded, easy to install and durable in use. Precision balanced rotor, smoothness for best reliability. Specification: Material: Metal Size Chart: Size: 10x3.6x3.6cm/3.93x1.41x1.41 inches Package Includes: 1 Piece 540 55T Brushed Motor : Please allow 1-3 cm/ 0.39-1.18 inch difference due to manual measurement and 3-5 g/ 0.007-0.01lb/ 0.11-0.18oz for the difference between different colors. Colors can appear different depending on light and how the listing is viewed. Thanks for your understanding and attention. Wish you a pleasant shopping experience!