MPF Products BA 150, BA 151, BA 152 Rechargeable Battery Replacement Compatible with Sennheiser IR and RF Wireless Headsets (Compatible Models Listed in Description Below) Replacement for the following Sennheiser battery model/part numbers: BA150, BA 150, BA-150, BA151, BA 151, BA-151, BA152, BA 152, BA-152, CPH-522, CS-SBA150SL, WEST-BA151. Compatible with the following Sennheiser IR and RF wireless headphones models: A 200, HDI 302, HDR 4, HDR 4-9, HDR 45, HDR 60, HDR 65, HDR 80, HDR 85, HDR 400, IS 150, IS 300, IS 380, RA 85, RI 150, RI 250, RI 250J, RI 250S, RI 810, RI 810 S, RS 4, RS 6, RS 8, RS 30, RS 40, RS 45, RS 60, RS 65, RS 60, RS 65, RS 80, RS 85, RS 400, RS 2400, SET 20, SET 50 TV, SET 250, SET 250J, SET 500, SET 810, SET 810S, SET 820, SET 820S, SET 2500. 2.4V 60mAh Ni-MH Accupack Battery Pack. 1 Year Replacement Warranty. MPF Products is a Registered Trademark.