I am pretty sure this will fit in your S2+
I can check tonight, as I have this same host that is on my to-mod stack of projects.
*edit, I have reversed my description, so it should be proper. Thanks for catching that SaticX*
All clickys just turn on or off the power flow to the driver. The difference being if the momentary happens after the click, or before. All (stock) McClickys are forward, meaning that the momentary on happens as soon as you start pushing the light. With a reverse, you have to push until it clicks before you see light
One note, if you are going to buy this, do it today. RMM says he is closing down Mtn Elec for the rest of the week, starting tomorrow. Today is the last day he will ship until next Monday.