Adjustable Fit Wrist Restraints

Print with a flexible filament and use supports. It's pretty long and I had to print diagonally on my 220x220 bed. 

I used Sainsmart TPU clear(pretty flexible), with Cura default printer settings for generic TPU. It printed nicely with minor warping at the tie-on loop. I had to use a razor to remove the supports but there aren't many and it didn't take too long.

They are really quite strong and difficult to get out of provided the wrists are not within reach of each other.