Interchangeable with BLH Model LBG1. Same as Model BBS1, BBS2 and BBS2F. The boot is filled with an insulating grease. FM Approved. 2 mv/v, 0.03% nonlinearity, 810/750 ohm (50-1K), 375/350 ohm (2.5K-7.5K), 10 ft 4 cond cable, nickel plated steel. NTEP 87-087 S/M III 3,000 div.