伸縮規組，6件式 5/16 - 6"，PEC

Finally, a set that actually locks tight and stays put when you need to transfer a measurement. The 5/16 to 6-inch range covers all the odd-sized holes I deal with in the shop, and the plungers feel solid, not flimsy.

I was really impressed how smoothly the self-centering plungers lock into place, making it easy to get a consistent reading every time. These have been perfect for measuring deep recesses and grooves that my calipers just couldn't reach.

Finally, a set that locks down tight without that vague, spongy feel some cheaper gages have. The 5/16 to 6 inch range covers everything I need for engine block bores and valve guides.