These 16 ultra bright smart LED NeoPixels are arranged in a circle and have a 44.5mm outer diameter and can be chained together. Control with a microcontroller.16 ultra bright smart LED NeoPixels are arranged in a circle with a 44.5mm outer diameter. The rings are chainable – connect the output pin of one to the input pin of another. Use only one microcontroller pin to control as many as you can chain togetherEach LED is addressable as the driver chip is inside the LED. Each one has 18mA constant current drive so the color will be very consistent even if the voltage varies, and no external choke resistors are required making the design slim. Power the whole thing with 5VDC 4-7V works and youre ready to rock.The LEDs are chainable by connecting the output of one ring into the input of another. There is a single data line with a timing-specific protocol. Since the protocol is very sensitive to timing, it requires a real-time microcontroller such as an AVR, Arduino, PIC, mbed, microbit, etc. It cannot be used with a Linux-based microcomputer or interpreted microcontroller such as the netduino or Basic Stamp.NoteMay ship with either WS2812B or SK6812-based LEDs. They are the same brightness, color and protocol.FeaturesThe Neo Pixel rings are chainable, chain as many as you want together and control them with a single microcontroller such as the microbit/Arduino. Each LED is individually addressable.