伸縮量規套裝，4 件 5/16 - 2-1/8"，PEC

The locking mechanism on these telescoping gages is really smooth and holds tight, which makes transferring measurements from deep slots much less frustrating. I used the smallest one to check a stubborn recess on a repair job and it worked perfectly.

Finally got around to using these on some deep bore measurements and the self-centering action really does save time. The 4-piece set covers a decent range for my shop work. Locking them to a known size for a quick go/no-go check worked exactly as described.

These lock up really tight, so the measurement stays put when you pull them out of a tight spot. The range covers exactly what I need for checking bearing bores and other hard-to-reach internal dimensions.