The diameter requires a 15.495in Straight gas tube which is included. The width of the gas block is 1.15in length 1.0in Height from bore centerline to top of block is .945in. The increased height doesn't allow it to sit under most hand guards. The gas tube height is .86 which works with the and AR10. The overall length of the straight gas tube is 15.495in Specifications for Precision Reflex Adjustable Gas Block w/ Straight Gas Tube: Manufacturer: Precision Reflex Color: Black Fabric/Material: Steel Gun Make: AR Platform Condition: New Package Contents: Precision Reflex Adjustable Gas Block w/ Straight Gas Tube