Welcome @anotherhuman, I've been burned a couple of times in my life buying devices just because it had a money back guarantee and I thought I had nothing to lose. It was my fault for not reading the fine print. Actually there are some exclusions for the money-back guarantee for the ReBuilder - The guarantee is specifically for new, personal-use devices purchased directly from ReBuilder Medical. The guarantee does not extend to refurbished or discounted devices, or purchases made through distributors or professionals. -- https://rebuildermedical.com/guarantee. Not a problem if the device works and helps you but a major cost if it doesn't help your symptoms.

They do? Because my Chiropractor refused to refund my money.