Instructions:
1）Implementation of standards：JIS R7202：2008
2）Material: GCr15， Measuring surface hardness 60-63HRC;
3）Comes with the calibration certificates .
How to order?
For example:
Pls mark : 600T4N or 317T4N    Ring & Plug & Master Gages,  7 pcs / sets,
and E-mail to: edwin@szfyou.com