Standard Abrasives 875702, MD Mini-Brush, 4-1/2 in x 4 in x 5/8-11 FB036 A XCS Medium Density, 7010369376 
Insize 1129-300, DIGITAL DEEP HOLE INSIDE GROOVE CALIPER, 0-12″/0-300mm, 6928640392528
$589.06
Resolution .0005″/0.01mm
Measure diameter of grooves inside deep holes
Buttons: on/off, set, inch/mm, preset(+,-)
Automatic power off, move the digital unit to turn on power.
Battery CR2032. Data output.
Made of stainless steel.
Optional accessory: data output cable