technically microbore is 8mm or less, we use a 6mm microbore that is triple layered out to 11mm (outside diameter). Its much lighter and easier to use than standard hoses like tricoflex etc but ours is completely different to what the likes of Gardiners etc sells so I can't say what theirs are like although I've heard good things. Our microbore is unkinkable (yes I know some will laugh and say yeah right but I can assure you that after using it for over a year we have not had one kink, the hose is still in really good condition (prob another 2/3 years life left in it). Other microbores may kink but you'd need to try it first.