The UniqueTek Micrometer Powder Bar Kit upgrades your existing Dillon powder bar to a micrometer powder bar. No more guessing how many turns of the adjustment screw will get you back to that perfect powder weight.   Features  Precision micrometer head Durable all-metal construction Fits Small, Large, Ex-Small & Magnum powder bars Fits Belted Magnum powder bar and SL 900 Shot Bar (minor modification required) Works with all Dillon presses that utilize the Dillon Auto Powder Measure (e.g. Square Deal B, AT-500, RL 550B, XL 650, Super 1050 and SL 900)  Specifications   Thimble Size  0.5 inch diameter thimble    Thread Pitch  40 thread per inch  (replaces the 28 thread per inch bolt)    Precision  .001" per division  ( .02 grains Win 231 in Small Bar)    Range  0.000" to 0.750"; linear travel  (allows full range of adjustment with all powder bar sizes)  Fits all Dillon powder bars including the Belted Magnum powder bar.  Also fits the SL 900 Powder Bar and SL 900 Shot Bar!   Much more than just a dial or knob ? the Micrometer Powder Bar Kit replaces the original 1/4-28 adjustment bolt with a true precision micrometer with 40 threads per inch. You will be able to return instantly to any powder weight setting with an accuracy never before possible. Of course, you still must weigh and confirm all powder weight setting changes.    Kit includes micrometer head, LocTite and installation instructions. Powder bar not included. Plus, we send a FREE Excel spread sheet you can use to generate "calibration curves" for each of your gunpowders. With a calibration curve, you can predict the micrometer setting to give you any desired charge weight for that gunpowder.