This is the Mares MRS Plus Weight Pocket System PAIR Features: 1st Mechanical Weight System Fits Mares BCD's: Dragon, Dragon AT Hybrid, Hybrid AT, Hybrid Pro-Tec, Hybrid Pure Kaila Prestige MRS Plus, Prestige AT BCD's Durable Polyester 600 and ABS Plastic Construction Newly-Designed Buckle System Large, Zippered Opening Allows Easier Insertion of Weights Hook and loop Internal Closure: Prevent Weight Shifting Spacious, Simple, and Easy-to-Use Weight Capacities: 13 lbs. (6 kg) Fits Medium, Large and X-Large Size BCD's 8 lbs. (3.6 kg) for X-Small and Small BCD's MRS Plus Mare's evolution of the 1st mechanical weight system introduced to the market It incorporates a newly designed buckle system, one pull movement to release your weights, shaped pockets to form to your waist. Large, zippered opening allows for easier insertion of weights. Max load in the large size of 13 lbs. (6 kg) fitting medium, large and extra-large size BCD's and 8 lbs. (3.6 kg) for extra small and small BCD's.