Round Candle Track StopsRound 0.50 dia. x 0.225 (13 x 22mm) When it's time to lower the sail, you can trust the Davis Round Sail Track Stop to hold your sail and its slides in place on the mast and boom. Large knurled wheels release easily. Made of heavy duty black anodized aluminum and marine nickel plated brass. . Product: DAVIS 2350 SAIL STACK STOP ROND. Manufacturer: DAVIS INSTRUMENTS. Manufacturer Part Number: 2350. UPC: 011698235001.