Covers are supposed to do two things: keep heat in and stop vapour from escaping. Mine does neither. The measurements are DIY and the company makes no effort to contact customers or double check before proceeding with the order. They also had no problem selling me a thin cover (which seemed necessary because we have a lifter) but made no attempt to point out that the thin cover is totally unacceptable for Canadian winters.
They hide behind a strict "no returns / exchanges" policy despite having made no attempt to ensure that what they were selling me was the right product for my needs. And good luck getting someone on the phone or getting them to respond to an email. Be prepared to embark on a campaign before they respond.
They are not the only option out there nor are they necessarily the best price. Do yourself a favour and use someone else, or, BUYER BEWARE!