The Fowler-Bowers Holemike Bore Gage Set offer an economical solution to accurate shop floor bore measurement. Fast, accurate and easy-to-use, the wide application range of the Bore Gage line may be purchased individually or in sets. Included in this set are the following... 0.080" - 0.250" / 2-6mm Measuring Range 0.00005" / 0.001mm Resolution 5 Measuring Heads 1 Handle 3 Setting Rings Features include... 2-point contact point heads IP67 Rated Protection Ratchet Stop for consistent measurement Bluetooth Output Send data directly to a Bluetooth cell phone or Tablet with the FREE Sylvac BT Smart app.