The Infrared Plug is a small board which can send and receive modulated infrared signals, as commonly used by many remote controls and appliances around the house.
The board uses a CMOS 555-timer chip to generate the 38 KHz carrier frequency, and requires no further adjustments due to the use of 1% precision parts. An on-board transistor controls one or two IR emitter LEDs (≈ 50 mA for one LED, or ≈ 10 mA for two).
The Assembled Infrared Plug comes with the SMD-sized 555 chip and support components already soldered onto the board. Two IR emitter LEDs and an IR receiver sensor are also included, for mounting on the board or for connection via short wires. Headers for this and all other JeeLabs plugs can be found here (straight) and here (right angle).
The PCB Only version contains just the printed circuit board for the Infrared Plug. No parts, no headers.