With turn-to-fit hand clamp, DryLin W linear guides let users decide whether standard clearance is acceptable or if unit needs to be pretensioned. Tolerance can be modified over entire bearing surface by inserting provided Allen key into adjustment screw in side of carriage. Completely lubrication-free and contaminant-resistant, bearings come in hard-anodized aluminum, single- and double-rail configurations. Self-lubricating triboplastic helps carriages glide smoothly.