Mitutoyo SJ-411 / SJ-412 Surface Roughness Tester Deep Hole Stylus The Standard Detector for the Mitutoyo Surface Roughness Tester model SJ-400 series has an overall length of 44.7mm. This Deep Hole Stylus for the Mitutoyo SJ-400 Series of Surface Roughness Testers is two times the length of the standard stylus, allowing you to measure the surface roughness in hard to reach locations. This Deep Hole Stylus works with Both The SJ-411 & SJ-412. Features include... 3.73" / 94.7mm long 2μm Tip Radius Groove Depths up to 5.2mm deep 60° Tip Angle