This is the Aqua Lung Surelock Weight Pouch 10 OR 16 lb Weight Capacity Features: Easy to load design Remains secure until you want to release it Sure-Lock II Weight Pockets align themselves easily: Insert the pocket until it clicks Simple single-pull release to jettison weights in an emergency Use with soft or hard lead weights Construction: Durable nylon and impact resistant plastic Multiple weight capacities 10 lbs. (4.5 kg) two-weight capacity 16 lbs. (7.26 kg) four-weight capacity Taped and sewn edges add strength and durability 16 lbs. (7.26 kg) pouch has side webbing handle for easy transport Sold as Single Pockets The Aqualung Replacement Sure-Lock Weigh Pouches are available in 10 lbs. and 16 lbs. (4.5 kg. and 7.26 kg) weight capacities in each pouch. The Sure-Lock Weigh Pouches work with soft or hard lead weights.