Spring-loaded plunger expands within the bore (or groove), allowing determination of the internal diameter (or groove width)
With a knurled clamp

Technical Details

Size (LWH): 7.5 inches, 4.75 inches, 0.5 inches
Product Details
Product Dimensions: 7.5 x 4.75 x 0.5 inches
Shipping Weight: 0.19 pounds (View shipping rates and policies)
ASIN : B0006J428Q