as a cocker owner, i'm 99% sure the microlines are the small thin hose's on the front of the 3way on a cocker/dc2
as everyone else says the Macroline it the stronger, hose from the ASA(air tank bit) to the reg
Micro line is a plastic hose using push fittings, similar to macro but with a much smaller internal bore. It had a higher working pressure than the original LP macro used by Smart Parts on the Shocker 4x4 but new higher pressure macro made it redundant.