Newport optical mount rail CL-6 + 1/4" tripod knob Description: Total length (including curve) is 167mm. Non-curved length is 127mm.Groove length 101mm. Groove width 6,7mm (ready for M6 screws). Total width 25,6mm. Final curve inclination about 70º. It includes an adjusting screw with plastic tip to avoid damaging parts and a big thumb 1/4" thread knob to attach to breadboards and other optical stages, mounts or similar. PRICE is for ONE mount rail and ONE knob. Condition: may show some marks of normal usage here and there, but otherwise very nice. Shipping costs: I combine items to get cheapest shipping costs. Ask for invoice before paying your basket.