OD: 1.47"  or 37.4mm,  ID:  9/16"  or 14.2mm,   W:  1.89"  or 48mm

-  This insertcap fits inside the Tactical RIS Handguard, for attachment of recon or 9/16 inch barrel (RAP4, RAP5 and Xpower).
-  Comes with 8 x M4x6 socket set screw, Driver: 2.0mm