The belt material has been specially chosen , to stop anti slip and assist in causing the belt not  to expand .This means  that unlike most of its contemporary s  will not become 'soggy' and cause the webbing to slip through, the buckle . As most divers are aware , you then have to lay face down under water adjusting the tension as you would lose the weight belt ,which is highly dangerous , and with novice divers can lead to panic 

As Seal is a manufacturing company and does not need to import from China ,or elsewhere ' ,  so can control the quality and does not use a middle man or shop ,to retail as as result the benefit of price can be offered to you