The bore of the shaft diameter range 3/4", 1-1/2" to 3-1/2" and 2-1/8" to 3-11/32". Size range 75, 150 to 350 and 215 to 334. For the ring series: 5100, 5101, 5102, 5108, 5555. Durable construction There is such a wide variety of retaining pliers, available individually or in sets, to handle many applications. These particular pliers are for the use of external retaining rings.