Optiparts heavy duty buoyancy bags, according to IOD’95 rules. These bags
are made of polyurethane coated nylon and are about half the weight and
significantly stronger than bags made of PVC or PVC coated nylon.
Some bags are available with a twist lock tube valve. This valve is attached
to a piece of tubing. With this valve the bag can easily and quickly be inflated
and deflated. 
43 liter sizes: 27 x 88 cm inflated, 41 x 100 cm deflated