For bonding of larger metallic bodies that require an aluminum connection for compatibility such as mechanical units, copings, roof to cable tray and antenna frames2 x 4-3/16 x 0.1 in aluminum base plate has over 4 sq-in of surface contactAccepts all main size conductors up to 5/8 in DiaBi-metallic mechanical connector provides 1-1/2 in of contact length with conductors#18-8 stainless steel ribbed neck 3/8 in bolt with low profile #4 phillips head is pre-driven into the lug to prevent rotation during installation