DRUM IS A USED TAKE-OFF FROM A NEW PROCESS TRANSMISSION HUB HOLE IS 9 1/2 X 2 3/4 X 5 THIS DRUM IS FOR AN E-BRAKE WITH THE EXTERNAL BAND AND IS VERY HARD TO FIND WILL WORK WITH BOTH A 1350 AND 1410 FLANGE AS SEEN IN ONE OF THE PICTURES, THERE IS A SMALL CRACK NEAR EACH OF THE BOLT HOLES IT DOES NOT APPEAR TO GO ALL THE WAY THROUGH THE DRUM AND SHOULD NOT EFFECT THE FUNCTION OR PERFORMANCE OF THE DRUM THE PART # IS CASTED INTO THE DRUM 179927R1. PLEASE SEE OUR LISTING FOR PART# P2N61 SPICER HUB F 3-1-619 IF YOU NEED THE HUB FOR THIS E-BRAKE DRUM. YOU CAN ALSO CHECK OUT OUR STORE.