Sleep trials exist to ensure you’ll be happy with your product for the long haul. You’ll want the sleep trial to be no less than 90 days, as your mattress will soften slightly during the first few weeks you use it. Perhaps the most important part of the sleep trial is the money-back guarantee. You want to make sure that your sleep trial comes with a satisfaction guarantee that allows you to return the undamaged mattress for a full refund for any reason. Some manufacturers may place restrictions on their return policies, so it’s vital to read the fine print.