New modular backpack for perfect weight distribution. Its anatomical shape provides a better fit. Special handy weight compartments with openings for water drainage. Option to change the buoyancy with standard 500 g or 1 kg weights, up to a maximum of 4 kg. Adjustable, padded shoulder straps feature quick-release buckles for greater security and quick release in an emergency. Flexible line for fastening to the belt provides greater stability, with the quick release system.