Well, I just checked Allied and Newark-In-One (pretty much the main places to go for that stuff) and neither one had any hour counters that were resettable.
What are you trying to do? If I knew more, I may be able to give you some idea. When do you want to reset, and why?
The main problem you're going to run into is that an hourmeter is used on equipment like an odometer is used on a vehicle, and is an indicator of how much it's been used. Replacing an hourmeter on industrial equipment (unless it's non-functional) is just about as fraudulent as rolling back an odometer, so a resettable is something that's like to take some looking for, or you'll just have to make one yourself...
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