The first time I used the larger tool the rubber strap snapped. Inside I can see there are only 3 cords and they are all off to one side. I applied twice the force to the smaller unit and it didn't break, but it didn't work either.
I watched the RMATV video for motorcycle shock bladder replacement. The video recommends using this tool to remove the bladder cylinder. Bottom line, the strap broke. Unlike, more professional models, the rubber strap doesn't have many reinforcing cords running through it.