Pre-Purchase Checklist: Works in a single-pole or 3 way setupl (Not 4 way); Use only one ELEGRP dimmer switch in a 3-way circuit, the other side should be normal standard light switch; The device will not function if the neutral wire is not connected; Do not fit for smart bulbs. Adjust the low - end trim to set the minimum brightness, ensuring that the lights no longer flicker at the lowest brightness level.