Flared edges help prevent sharp surfaces from coming into contact with the pipe. Recommended for the suspension of stationary non-insulated copper tubing lines to prevent electrolysis. Felt lining also acts to reduce noise in pipes. Retained insert nut helps ensure the loop hanger and insert nut stay together. Manufactured to use the minimum rod size permitted by NFPA® for fire sprinkler piping. Conforms with Federal Specification WW-H-171 (Type 10), Manufacturers Standardization Society (MSS) SP-58 (Type 10).