Power module only for AT803b, AT831b, ATM73a, ATM75, U841A, U851A, U853A(W), U853A(W)U, U857A(W)U. Belt pack type power module, 1,5V AA battery & phantom , with low frequency roll-off, input on TA3M, output on integral XLRM 3-pin. Furnished with U853, U857A series and U841A and U851A