Paul Component Disc Adaptors are made in +0mm, +20mm and +40mm sizes and are compatible with either post mount or IS mount front and rear mounts. Features: Paul disc brake adapters allow for the use of larger rotors Made in the U.S. from aluminum and heat-treated steel IS Mount adapters are for frames where the mounting screws install horizontally Post Mount adapters are for frames where the caliper mounts directly through the caliper holes Specifications: Frame Mount Options: IS Mount (International Standard, 51mm), Post Mount (74mm) Caliper Mount: Post Mount (74mm) Color: Black Weight: 15g (+0mm | IS Mount), 21g (+40mm | Post Mount)