Posted by a reviewer on Amazon

Mattress encasement fits perfectly however there are no directions as to where to install the zipper

Posted by a reviewer on Amazon

I had to rely on illustrations from youtube

Posted by a reviewer on Amazon

The description says for boxsprings 7 to 9 inches deep

Posted by a reviewer on Amazon

I thought the cover might stretch from 7 to 9 inches so it would be taught around the boxsprings

Posted by a reviewer on Amazon

The cover would fit a boxspring any depth up to 9 inches

Posted by a reviewer on Amazon

I suspect any of the covers that fit a 9 inch box springs would fit the same way

Posted by a reviewer on Amazon

You cant tell it unless you get close to it and look carefully though

Posted by a reviewer on Amazon

Not sure about xl twins dont know how much longer they are than normal twins