The probes referenced in Table 9.1 and illustrated in Figures 9.1 and 9.2 shall be used as measuring instruments to judge the accessibility to uninsulated live parts and film-coated wire provided by openings and not as instruments to judge the strength of a material. Force is not to be applied to the probe when judging accessibility.

Technical parameters:

Head Length: 12.7mm(1/2 inch)
Total Length: 101.6mm(4 inch)
The Head Radius: 14.3mm(9/16 inch)
Former Head Diameter: R4.8mm(3/16inch)
The Tail Diameter: 19.1mm(3/4 inch)
Reference: UL507(135A)/UL1026(PA130A)/UL1278