Specialists in service and repair of industrial electrical installations will appreciate, I think, a convenient small-sized probe – “kontrolka” on 220/380 V. Indicator is not “neonka”, and the thyratron MTX-90. And as for the case, fit any size transparent (plastic or glass) bottle from under the drugs. Moreover, if the material of the “case” glass, to protect its integrity (for example, in case of an accidental drop) I recommend to wrap the probe in two or three places with electrical tape (in the form of shock-absorbing rings). Well, at the styli wear a PVC tube.
The appearance of small-size probe – “friendlies”:
1 — housing (clear bubble under medication), 2 — damping rings out of tape, 3 — plug, 4 — flexible wire insulation (2 PCs.), 5 — a feeler gauge to “0” 6 — probe “phase”, 7 — probe (thick tinned copper wire, 2 pieces), 8 — touch plate.