Lumb borthers Diving Weight Harness, FULLY ADJUSTABLE (some other cheaper models aren't) to be worn under a BCD. Comfortable and secure, the weights are held in a sturdy pocket which is velcro into a pouch either side which, when the harness is adjusted to fit you should sit just below your BCD where they can be quickly released by pulling forward.
This Bowstone Harness Weight Belt system has always been our favoured option for anyone needing a greater amount of weight, the larger diver or for small ladies who find standard weight belt systems just not comfortable.