25KG Lifting Bag with a 0.4 litre 232 bar mini-cylinder

http://www.cormetondivesupport.com/images/th-lb251801314361934.jpg
 The mini-cylinder is easily refilled from your main cylinder prior to the dive. 
The self-sealing baffle allows air to be added to the buoy from your DV or air-gun and prevents deflation at th surface. The dump valve prevents over-inflation. 

Available with DIN or International A-clamp