Pencil Probe
Pencil Probe are used to measure remainin wall thickness of pits as well as measuring thin walled material.

10 MHz x 3/16″ | 1/16″ Tip on delay line | Microdot Top | Good for Flaw Pit Depth Measurement
10MHz x 3/16″ | 1/16″ Tip on delay line | 90 Degree Right Angle | Microdot Side
15 MHz x 3/16″ | 1/16″ Tip on delay line | Microdot Top