Every Microstart we have, which adds up to about six or seven now, we got directly from the company, and every one works perfectly, including those we've seriously abused combining in threes and doing field welding at the Overland Expo. Obviously no such product is 100 percent reliable, but ours and all those of everyone I know who has one are excellent. I've started everything from a 460 Ford V8 and turbodiesels down to motorcycles.