Sunbeam heating pads are great for soothing your sore muscles after (or during) work, and you can score an electric one for just $4 right now. It’s actually marked down to $5, which would be an all-time low on its own, but the 20% coupon on the page will bring that down to $4 at checkout. The only catch? It’s an add-on item, so it’ll need to be part of a larger order.