The X-100 pack (mono to stereo adapter not displayed). X-100 sender (left) and receiver (right), same shape and size. Receiver is eqquipped with both 1/4 and 1/8 audio jack. Size of devices vs hand, so small it fits everywhere! Dual switch of the sender for pre-amp and the -3dB module. Potentiometer on sender to control pre-amp volume. This solid metal case assure safe transport, and looks pretty neat! While devices are paired and streaming, blue LED is on. Both devices have 3 LEDs : blue, green and red. Blue and Red are combined. Sender mounted on Fender Jazz Bass. 8 units setup for stage concert. The receivers (red circles) are plugged in the console while sender are plugged in musical intruments. Each unit is READY TO ROCK!!