I agree Karol, but that's not going to happen until my OEM (#4) module dies for some reason?

Also, wanted to add that I would shop that price around myself. If you take the # 3 and 4 modules out of the picture, the rest of the Rcexl modules with spark plug boots that fit the CM-6 plug are the same. There's nothing special about them, and you can buy them anywhere - for less than 50.00 as a rule. Sometimes much less? They'll all work fine on the 20 or 30cc DLEs.