OD: 1.47"  or 37.4mm,  ID:  1"  or 25.2mm,   W:  1.89"  or 48mm

-  This insertcap fits inside the Tactical RIS Handguard, for attachment of tactical or 1 inch barrel.
-  Comes with 8 x M4x6 socket set screw, Driver: 2.0mm