Fiber Optic Cable Tester Checker Model 5KM Fiber Optical Test Pen Visual Fault Locator for FC/SC/ST Universial Connector

Buen prodcto

Works great for acupressure points

Really does what I need. Thanks!

I bought this VFL for 2 reasons. It is smaller than other cylinder VFLs since it uses 2x AAA batteries instead of AA. It also has the on/off button on the bottom. Most of the other cylinder VFLs have a plastic button on the side that gets too easily bumped on which drains the batteries. The bottom button is a master on/off button. You have to click it, then use the mode button on the side which cycles between solid/fast blink/slow blink/off. Batteries were not included.Edit: I just bought and received 2 more. There seems to be a little trick to get these working. When I first insert 2x AA batteries, the device will not turn on. Push bottom button ... then push side button. I have to sort of prime the battery compartment by pushing the batteries as far as they will go by using a third battery or something else.Edit2: I have found that the battery contact point on the bottom cap developed a corrosion layer. This caused loss of contact with the battery and unit would not turn on. I scraped off the corrosion layer and applied a little bit of oil for protection.