The A1 collar is designed to fit as wide a range of pinned and welded brake outside diameters as possible and can effectively be mounted within the following size range: .855'' to .872'' diameter. Diameters outside the ranges listed may need additional gunsmith work to be fitted or may not be used with this product. Measurements should be taken from the circular section of the brake marked with the 'LANTAC' logo.
The A1 Adapter Collar ships with a vial of Rocksett that must be used to ensure all mounting set screws are retained in place when the adapter is mounted to the brake.
The A1 Collar is rated for 100 rounds of continuous fire max. The device must then be allowed to cool. Check set screws regularly to make sure they have loosened. Do not work with DGN556B-QM.