I have a Makita 3621C Router and am in the process of purchasing a Leigh Dovetail Jig D4R. They supply some router bits with the standard kit. My Makita 3612C router was purchased in South Africa. Do the sizes of spindles for router bits vary or are there only two sizes - 7.5mm (1/4") and 12.7mm (1/2"). My router takes a 12.7 mm bits. In ordering a Leigh Dovetail Jig from the USA, what size should the spindle be for router bits to be sent? Will those supplied in the kit fit my Makita? Any help will be appreciated.