Arch Up

What equipment are you guys using to perform Arch Ups?

I can use my lounge or table but haven't figured out how to lock my legs in place

I used stall bars to lock my legs under.

My sofa has strong arms so I use that, I create an anchor for my feet by using a belt tied in a loop around the pull-out bed structure under the cushions.

Hope I've explained that well.

I have a home made plyo box I can use. I put a couple of 2x4s under it to raise it up a bit and use a strap tied to an anchor point to hold the feet.