What is an Infrared Emitter?
An infrared emitter, or IR emitter, is a source of light energy in the infrared spectrum. It is a light emitting diode (LED) that is used in order to transmit infrared signals from a remote control.

If you're interested in home automation, these IR receivers and transmitter will solve a lot of your problems working with arduino, raspberry pi, etc.You could use these guys to build universal remotes that control all the devices in your home too!

Features
Including LED IR emitter and receiver
Widely used in remote control and other remote devices
Nice and simple to use, downloaded the IR remote library for arduino and with a simple sketch had this up and running

The Dimention of the IR Emitter:
Working Voltage:2.7~5.5V
Forward Voltage: 1.2-1.5V
Forward Current: 100mA
Power: 100mW
Frenqence:38KHz
Receiver Angle:±45°
Lens Color : Water Clear
Operate Distance:18~20m
Pin length: Approx. 25mm / 0.98"
Total Length approx. 30mm
Peak wavelength (nm): 940nm
Operating temperature : -25~ +70 ?

The Dimention of the 3 legs IR Receiver
Model : VS1838B
Working Voltage : 2.7~5.5V
Low/High Level Voltage : 0.4V/4.5V
Receiver Distance : 18M
Frequence : 38KHz
Receiver Angle : ±45°
Bulb Size diameter : 5mm / 0.2"
Pin Length : 22.5mm / 0.88"
Epoxy resin package plus external shielding anti-dry design
Anti-dry ability, able to withstand the environment dry scratch
Output match TTL, CMOS level, active low

Application:audio-visual equipment (speakers, TV, DVD, satellite receivers, etc.); household appliances (air conditioning, electric fans, lighting, etc.); and other infrared remote control products.
Package Includes
5 Pair Infrared LED Diodes