Yes, these twist on but a wrench or crescent wrench helps a lot to get them tight.
This piece is actually 2 pieces, the inner and outer piece.
The inner piece comes out of the outer piece.
You thread the outer piece over the hose cover.
Then you thread the inner piece into the hose and outer cover (the outer piece has a threads at the front for the inner piece to thread into and then it goes into the inside of the hose if this makes sense).
The inner piece forces the hose between the inner piece and the outer piece and is a very strong fit, I have used these many times and the hose never failed at that threaded repair piece, not one time.
I keep some of those reusable hose ends in my tool box but don't repair out in the field.
Easiest way I found is use a metal cutting chop saw to cut the hose so the end is square and then thread the outer piece over the hose end, then put some vaseline into the hose and over the inner piece then thread the inner piece into the outer piece threads and into the hose then you are done.
This takes about 10 minutes if you have the chopsaw, you can probably cut it with an angle grinder but it might fray too many wires and leave the end of the hose all frayed and it will be hard to use this repair piece as the outer piece has to go over the end of the hose and if it is frayed badly this piece might not go over the hose. The chopsaw makes it a lot easier to repair.
These are about $8.00 more or less so keeping some in your shop would be a good idea for those repairs at odd hours to get back to work if you don't have the spare hose on hand.
I have not looked but there might be a youtube video showing this, they have millions of videos there, you just never know.
Hope this helps.