The wasp wcs3900 barcode scanner series are the most popular ccd barcode scanning devices in the wasp product line manufactured for durability yet employing an exclusive ergonomic design for comfort the wcs3900 and wcs3905 barcode scanners are the best in their classfor fast connection the wcs3900 can simply be plugged into a keyboard wedge via usb or ps2 both barcode scanners send data to an active application just like it was typed on a keyboard they are designed for retail point of sa