NooElec PL2303 USB to Serial (TTL) Module/Adapter with Female and Male Wiring Harnesses & Test Jumper. Compatible with Windows 98 Through Windows 7; Mac OS 8 Through OS X, Linux and Android!
A handy USB to TTL converter based on the PL2303.
3 LEDs are on-board to indicate power, data reception and data transmission. A 5V and 3.3V output is available--you can power your project directly from the USB port, so it functions as a USB power supply, too. The 5-pin I/O is clearly labelled on the board.
Both a 5-pin female to male and a 5-pin female to female multicolor jumper cable set are included! This will allow connection to Arduino, breadboards and nearly any other board with standard male or female headers.
A shunt is also included in order to connect TX and RX to conduct loopback testing.
Excellent driver support--drivers are available for Windows 98 to Windows 7 (32 bit and 64 bit), Mac OS 8 to OS X (32 bit and 64 bit) and Linux. Even Android is supported!