what size tube to bleed the clutch?

[matlee]

I bought one of those one man bleed kits off the bay and its worked fine on the brakes but the pipe supplied with it is too small to fit over the bleed nipple of the clutch. What size piping do i need for this? I would measure it myself but im away from home until next weekend and hoping to get the tube before then so i can get the job done that weekend.