The BT-100U Cash Drawer Trigger is designed to provide a USB interface for the cash drawer. This allows a cash drawer previously connected to a POS printer or cash register to be connected directly to a computer's USB port. This means that when a printer is not used in the POS system, the cash drawer can be connected directly to the computer via a USB trigger. The BT-100U USB trigger module uses a virtual serial port driver to make it look like a standard RS232 serial port in software. This way, existing POS software can communicate with the USB Cash Drawer Trigger as if it were connected to a serial port. Each USB trigger module is assigned a unique serial number, and the driver software assigns an available serial port to each device it recognizes (multiple triggers can be used on one computer). The cash drawer can be connected directly to the computer with the BT-100U USB bus, without the need for external "hot swapping", a plug and play connection that works with any cash drawer without setting COM properties. Colour:Black material:plastic Package contents:1 x BT-100U Cash Drawer Trigger Only the above package contents, other products are not included. Note:Lighting and different monitors may cause the color of the item in the picture to be slightly different from the actual item. The measurement allowance is +/-1-3cm.