These are the smallest NeoPixel breakouts around! Tiny, bright RGB pixels to your project. These little PCBs are only 8mm x 10mm and have two sets of three pads on the back for soldering wires. These ultra-bright LEDs have a constant-current driver cooked right into the LED package! The pixels are chainable - so you only need 1 pin/wire to control as many LEDs as you like. 

These pixels have full 24-bit color ability with PWM taken care of by the controller chip. Since the LED is so bright, you need less current/power to get the effects you want. The driver is constant current so its OK if your battery power changes or fluctuates a little. 

Each pixel draws as much as 60mA (all three RGB LEDs on for full brightness white). An Arduino can drive up to 500 pixels at 30 FPS (it will run out of RAM after that). Using ribbon cable you can string these up to 6" apart (after that, you might get power droops and data corruption) 

Each order comes with 5 individually controllable pixel buttons.

Adafruit has a detailled NeoPixel Uberguide.

• Dimensions: 8mm / 0.3" x 10mm / 0.4" x 3mm / 0.1"
• 0.4" (10mm) diameter circle PCB, 0.1" (3mm) total thickness
• Weight: 0.3g
• 800 KHz speed protocol
• Chainable design
• 5 VDC power (can run as low as 3.5V but color will be dimmed), constant current 18.5mA per LED (~55mA max total per pixel)