Fowler, 52-565-038-0 Hold-Tec Holding System with Fine Adjust All accept 3/8" indicators Mag base and HOLD-TEC with fine adjust also accepts 8mm indicators All have dovetail clamps for test indicators Mag base features 2 fine adjusts making it a 6-Axis Mag Base HOLD-TEC can be mounted in drill chucks, collets, dial gage stands with 8mm mount diameter to make a quick transfer stand Mag base has 180 lb. pull Adjust to any position Powerful On/Off mag base Central locking system