Dental Ex-Probe, XP23-W. Stainless Steel Handle. This Ex-Probe is an excellent combination instrument for dental diagnostics. It has an explorer tip (EXS 23) on one end and a probe tip (William W) on the other. The probe tip has markings at 1, 2, 3, 5, 7, 8, 9, 10 mm. Product code: XP23-W or EXS G with Williams