Spreader bar

Spreader is used to keep legs and arms apart during BDSM play. It is a rigid bar, usually about 18-24 inches long that has multiple hooks or rings to attach cuffs.They are especially useful to people without bondage-friendly furniture.
Spreaders are also convenient when used for leverage during intercourse; you can pull the bar to bring your partner closer or just move it up and down to lift his/her pelvis off the bed.
Be careful, the bar is attached to the player's limbs. If you are looking to make an amateur dungeon, spreaders can be hung from the ceiling, as well as connected to a wall or the floor.

I read the reviews on those bars and they seem to be a bit flimsy. If you want some less flexible options, you might want to consider attaching that leather spreader bar to something more dense. Maybe a plank of wood or a sheet of metal.

If you're going to modify a spreader, it might be better to simply make your own. There are a few tutorials out there for making your own spreader bars from Home Depot materials. I constructed a 3' and a 1' set for about $20, they're very sturdy and I really love 'em!

I have always wanted to pick up, and try out one of these spreaders. They look like a lot of fun.