This infrared LED will shine in the infrared spectrum at 940nm. You can use an Infrared camera to pick this up or something more simple like a phototransistor with a IR filter (which can be found here ). Just like a regular LED you need to use a resistor to power this LED or you will burn it out.Manufacturer: VISHAY Manufacturer Part No: TSAL7400 Product Category: Optical Sensor ROHS: Yes Datasheet: Click HereSpecifications Wave Length/Frequency: 940nm Product Type: Infrared LED Package: 5mm More Information Same Spec Items – SKU A-1544 Manufacturer VISHAY MPN TSAL7400 Can be used with – Customer Ratings 4.7/5 Based on 5 reviews5 Stars 114 Stars 43 Stars 02 Stars 01 Star 0 Write a review Price Quality Value Aug 18, 2014 Fantastic These IR LEDs have served many purposes for me, from a TrackIR setup to Arduino-based Universal Remotes. They just work, and only in the IR spectrum. No super cheap red glow in these LEDs! Krizzen Price Quality Value Feb 9, 2013 Awesome LEDs! I used a couple of these with a nightvision camera I made. They work great, but the light could spread out a little more. About 8′ away from a wall, the light spread only about a 3′ (radius) circle. Overall great, just get several and angle them in multiple directions to get the best coverage. Brannan Price Quality Value Dec 23, 2012 AWESOME No visible light, very bright, low power consumption.Thanks will be buying more soon! DOMINIQUE Price Quality Value Sep 14, 2012 Fantastic Absolutely great infrared LEDs, no visible red at all unlike leds from other cheap sources, gotta buy till in stock. Buyer Price Quality Value Aug 31, 2012 Great LED, great price!! I used some of these in a nightvision headset I made, and they are really bright! They barely get warm.They could spread out a little better, but for 6 cents each, you can’t beat em’. Great job 100Electronics! Keep up the great prices and shipping. I hope you do well. Jesse