Big Horn 19234 Magnetic Dial Indicator Base Holder for Machinist Tools. Multipositional Magnetic Base with Fine Adjustment. Magnetic holder reaches up to 12" and produces 45 lbs. of magnetic pull. Attach this powerful magnetic holder to flat or round surfaces and with the turn of the knob you'll produce 45 lbs. of magnetic pull. The device reaches as far as 12" and includes a magnetic base, upright post swivel, upright post, swivel snug, gauge rod and indicator clamp. Knurled thumb screws provide a positive grip.