For 4", 6", 8" & 12" vernier and dial calipers. Features:For 4", 6", 8" & 12" vernier and dial calipers.Choice of 3" or 4" base length for 6" & 8" models.Finely ground base surface and secure locking clamp.LengthDescriptionOrder No.3"for 4", 6" & 8" caliper101-30014"for 4", 6" & 8" caliper101-30025"for 12" caliper only101-3003