Ultradyne Oversize Shrouded Timing Nut 1/2 x 28 1.0 BBL Black. Use this timing nut for those barrels up to 1 inch in diameter. Specifications for Ultradyne Oversize Shrouded Timing Nuts - 1.0 BBL: Manufacturer: Ultradyne Color: Black Fabric/Material: 416 Stainless Steel Diameter: 1 in Finish: SB Nitride Features of Ultradyne Oversize Shrouded Timing Nuts - 1.0 BBL 416 Stainless Steel SB Nitride Coating Package Contents: Ultradyne Oversize Shrouded Timing Nuts - 1.0 BBL Ultradyne UD10960: Oversize Shrouded Timing Nut 1/2 x 28 1.0 BBL Black