MK-8401 wrist strap tester for anti-static systems.
Tested and working. I'm not religious about static control, and in fact I'm extremely lax about it, but I do have sufficient equipment to set up an anti-static station if necessary. This tester passes if resistance in the system is between 900K and 35M Ohms. I've verified all three conditions, pass, hi-fail, and lo-fail.
Uses one 9V battery (not included.) No cables, wrist straps, or other accessories included.