These are similar to leather stretcher but they incorporate
lead shot packed into the stitched compartments so these do
generate a downward pressure to create stretch. They are more
difficult to lubricate, so not as effective in creating stretch as
steel, but they do have strong erotic appeal and combine that
lovely kinky attraction of black leather with the sexual hunger
inducing sensation of weight on the testicles.

As with leather thought needs to be given to the effect of sweat
and condideration given to lubrication. Talcum powder can be
used but some people's bodies will turn this into a kind of
grinding paste when combined with sweat. Individuals need to
experiment to find what is right for them.