Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: How long is the strap?
Document: These worked great for an extra long twin bed, padded top, the sheets are a bit small and these worked perfectly.
When my husband was sleeping, he moved a lot and cause the corner sheet come lose. So I've tried the straps and the strap did not hold in it place, it came lose.
Best purchase in a long time! These hold great and fit perfectly for the fitted sheets that don't fit well. Mine always had a tendency to slip up the side of the bed, but these hold tightly and do not damage the sheet like some other brands tend to do. I would recommend these suspenders to anyone thinking about trying them out.
I thougt I'll give ONE MORE corner strap a try, and voila - enter these!!! It's been over a week of putting the bed in every imaginable position, and having my dogs do their thing, and the fitted sheet is FINALLY staying FIRMLY in place. It think the secret is the *clamp-style* grippers AND the velcro stap. No kidding - these really really REALLY work! !
These are the straps to buy! Unfortunately, I wasted a lot of time and money on other products which always came loose. I was skeptical at first but was I desperate to find something to hold my contour sheets firmly on my Tempur-Pedic mattresses. We have two extra long twin beds and the sheets required for these beds are larger than most standard bed sheets. Because of that factor, the contour sheets were an even bigger problem to hold in place.
works on my hospital bed fitted sheets
love these. had the other kind and they were hard to put on. these are so easy to put on and they do the job, holding the fitted sheet on the mattress
Years ago I had seen a similar item in a gadget book. Every morning when I got up I had to adjust the sheet. This got VERY old over time. Found these on Amazon and after reading the reviews decided to try them. They are wonderful!!!! The sheet stays in place and I no longer have to adjust it every morning. This makes my morning routine much easier.
Worked like a charm. Kept my new soft sheets tightly in place. Wish I had ordered 2 sets in case my son's new sheets have the same issue with staying on the bed.
With sheets having such varying sizes now it is great to have a product like this to keep the sheets in place. I didn't have to lift the mattress to attach them. Easy on easy off. Worth the price.
Answer: From the end of the clips to the other end of the clip 12.5 inches. Stretched out is 20 inches end to end. I had suggested to the manufacture that he  make the openings on the clips bigger for blankets or quilts. The clip openings are only a 1/4 inch. Therefore, these are only good for sheets. We use 4 small pieces of denim wrapped around the sheets avoid tearing at the holding point.  They work well if done properly.