I use the X4 Lab attachment that allows for two straps at once, but I don't use straps. What I do is:
1. I stick a two inch screw that fits in those holes (you should see four total)
2. I buy those suction cups they sell on websites like wish. The blue ones. They usually come in three sizes Small, Medium, Large.
3. They usually come with those silicone things you apply like you would for the Phallosan. So apply that.
4. I will then use the end of the suction cup which has a metal hook at the end and put the screw through it to hold it all in place. I have a wing nut so the screw never falls out.
5. I use a wine vac to create a suction. The one I have fits perfect on those suction cups. They come wtih that Size Master pro kit.
You can wear this mod all day, but DON'T DO IT all at once. I had it on for four hours straight and got two big blisters on the head. Took like a week for them to go away, but it was super sensitive to the touch. Right now I'm doing one hour on and then a 10 min break and then re applying with no issues.
Hope this helps.