Woodcraft should not require a receipt, they are their own brand of warmer, so they know you got them from them. I called and spoke to a woman on the phone there, she said they know the old style cord was prone to coming loose(it was just an elastic band tied in a knot) and said they have come up with a much better new style cord and that if I send them in they would repair them no cost.

I bought the warmers new in 05.

As for the lap timer I am not sure what the new one has that this does not, I only used it for individual lap times.