Brooks Nylon Saddle Rain Cover (NEW Material) NEW Nylon Brooks Rain Cover protects your Leather Saddle from moisture. NEW Nylon Rain Cover is an improved version of the tradiitonal Rain Cover, building on feedback provided by the Brooks Community. REGULAR: ALL ROAD, MTB, TOURING AND TREKKING AND B66, B67, B72, B18 LARGE: B73, B190, B135, B33