[OPERATION METHOD]: Rotate the rotary rod to make the ball head expand until it expands to the diameter of the hole. Take it out directly and measure the expansion diameter of the ball head at this time to get the size of the hole
[HIGH PERFORMANCE]: The operation is simple and convenient. The adjustable ball head expansion structure is designed to copy the pore size, which is convenient for precise measurement
[APPLICATION]: It is used to obtain the exact size of holes and slots, which is suitable for factories, schools, offices and other places
Use Small Hole Gages with full ball to accurately measure small holes, slots, grooves, and recesses. Easy to adjust with full spherical, hard, satin-chrome plated measuring faces.