Special order from the MB dealer - full retail is like $35 for the tool. Seriously, the bargain of the century (my time is worth at least $35/month!). Knockoffs are on Ebay all the time for something like $25. The drip timing technique apparently works for some folks, but for me it was like friggin voodoo - way too many variables. When this tool clicks into place, there is absolutely no doubt where the pump it set, just dial the motor timing in to match and bolt the IP into place.