The smallest end of our billet separator range, with a 6.4 mm bore. At this size it suits fine hard line, small vacuum and gauge lines, and the tightest braided hose, all of which are prone to drooping and vibrating because they have so little stiffness of their own. Pairing two of them in a separator gives the run a defined path and takes the movement out of it. Fitting is simple: open the clamp halves, place the lines in the bores, and pull the fastener up just enough to grip without crushing. Measure the outside diameter of your line rather than working from the nominal size, as small-bore hose varies noticeably between constructions.