Brand: QVS. MPN: TR1284MK. AC power adaptor. Save money and avoid the inconvenience of replacing batteries. Also works as optional power adaptor for MSV12C, MSV14C, MK21FBP, MK22FBP, MK41FBP & MK22FBP IEEE1284 autoswitches. (Specification: DC 9v 600mA - 5x2.1mm Female)