Provides a warranty for his work, though haven't needed to use it.
Had a stove top element, oven, and dishwasher for a tenant that needed repairs, wasn't able to be there myself or double check that they weren't working because was out of town. David could have claimed to have fixed the oven and I wouldn't have known any better, but told me it was working fine, just the switch was acting up and didn't charge for it.
After two years, stove and dishwasher are still working fine.