Step 3 · Mount the Air Switch Button

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

Take the air switch button assembly from your kit. Typically, it consists of the decorative button top, a gasket, the main body, and a retaining nut. Unscrew the retaining nut from the body. From the top of the sink, place the rubber or silicone gasket over the hole, then insert the main body of the air switch button through the gasket and the hole. From underneath the sink, thread the retaining nut onto the switch body and hand-tighten it. Use a pair of channel-lock pliers or the plastic wrench that may be included in the kit to give the nut a final quarter-turn to secure it firmly, being careful not to over-tighten.