Inline Dimmer with Controller Switch for light LED lighting system. INSTRUCTION: DC power: 5.5mm x 2.1mm male & female connector Application Models: Twinstar: 300C, 300E(2018 and earlier Vr.), 360E(2018 and earlier Vr.), and 300EA(2018 and earlier Vr.) ​DC power: 5.5mm x 2.5mm male & female connector Application Models: Twinstar: 300E(2019 and later Vr.), 360E(2019 and later Vr.), 360EA(2019 and later Vr.), 600C, 450E, 600E, 900E, 450EA, 600EA, 900EA, 600S, 900S, 600SP, 900SP, 600SC, 450SA, 600SA & 900SA. HOW TO USE: *This product first needs to be “paired” with the light fixture for initial use to ensure it is working properly. To pair with the LED light, first it needs to press and “HOLD” the “ON/OFF” button for at least 5 seconds or longer. The pairing process is success when the LED stop flickering. FEATURE: 7 levels of brightness Different flashing light "thunder" modes can be toggled by holding the "Mode" button for two seconds CAUTION: For indoor use only. The unit must be protected from coming in contact with water.