Silicone Rubber Belt Round Pulley Power Transmission Belts 2MM 2.5MM 30MM 40MM 50MM 70MM 80MM 90MM Product Description Silicone Rubber Round Power Transmission Belts 2MM/2.5MM 30MM 40MM 50MM 70MM 80MM 90MM Specifications Size:2X19MM 2X30MM 2X40MM 2X50MM 2X70MM 2.5X80MM 2X90MM e.g. 2X50MM----Diameter of belt=2MM Diameter of Circle=50MM 2.5X80MM----Diameter of belt=2.5MM Diameter of Circle=80MM Color: Black Line diameter: 2MM/2.5MM Circle diameter: 30/40/50/70/80/90mm Material: Rubber Made in China Easy to install, suitable for model toy automobile with the pulley.Good preference for drive. Package Rubber Belt (Black) Choose your length and number