THE FERRULE IS MARKED WITH A TRIANGLE WITH THE NUMBER 2 INSIDE............AS YOU CAN SEE IN PHOTOGRAPH..............THE INSIDE MEASUREMENTS TAKEN FROM INSTALL SIDE.... OF FERRELL..... 1 1/2" WIDE.......1 5/8" TALL ....THE CIRCULAR OPENING MEASURES 1 1/8" .... THE AREA BELOW THE CIRCULAR FOR HAND GUARD WOOD TAB MEASURES......7/16" WIDE .....1 3/16" LONG.........................this ad is for one ferrule....the photo shows the two that are being offered ..you will be purchasing one....or both if you like...Com Block NOS, unissued reinforcement metal ring (AKA "Ferrule") for RPK wood or laminate lower hand guard. Fits all RPK lower hand guards (RPK-74, RPK-74M, RPK-47