CH340G USB A to serial adapter module, ideal for interfacing a USB to a micro-controller serial RS232.  USB power can be set to either 3.3 or 5vdc with an onboard link.  Uses a clone CH340G chip that is fully supported by most computer operating systems. Please Note: that there are reports that some newer drivers many not work on all operating systems.

Module size including header, 57.9mm long, 21mm wide, 11.5mm high

CH340G Driver Download