天天看片在线精品,亚洲中文欧美日韩在线卡,狠狠热精品免费观看,国产在线成人免费

Type O probe is also called ring yoke probe, it is designed by the principle of magnetic field, used to detect the irregular workpiece of bearings, pipes, vanes etc. When using, put the small workpiece in the ring, magnetizing it by magnetic suspend liquid, the cracks of bar will show out.