■ Product Name / Tension adjustment buckle & Rubber belt ☆ Selling Point Superior to the old-fashioned nylon weight belts. ■ Weight Belt Analysis Regardless of scuba diving or freediving, when wearing a general weight belt with lead weights, which are often found in existing products, you might think you've fitted it perfectly, but then you notice it has slipped down from where you put it. In freediving, you might find yourself floating on the surface or having to retighten the belt during a fun dive, or having to adjust the shifted weights back to their original position. This can be a source of increased stress when you want to fully concentrate on enjoying yourself underwater. The reason why the weight belt on your body loosens is because the wetsuit material is made of a material with countless air bubbles. When you descend underwater, the air bubbles in the wetsuit material are compressed by water pressure, causing the material itself to shrink. Therefore, even if you fit the weight belt to your body on land, it is theoretically impossible for existing weight belts to stay in place when you enter the water. ■ Buckle & Rubber Belt Features A strong spring is built into the internal mechanism of the buckle. As you descend underwater, the spring utilizes the force (elasticity) that tries to return to its original state from the stretched state of the wetsuit material, which is compressed by the water pressure. The buckle itself automatically corrects the tension on the belt. By simply applying tension to the spring inside the buckle before entering the water, the weight belt will always stay in place, even during freediving, where you repeatedly descend and ascend. The belt material is a familiar rubber belt for spearfishermen, but it is a material with low recognition among scuba divers who have only used nylon weight belts. It is made of rubber using the same manufacturing method as tires, with a unique blend of natural rubber, graphite powder, and vulcanizing agents, placed in a mold and hardened by high-temperature steam pressure. Similar to the durability of tires, the weight belt will not stretch during diving. ■ Size Belt Total Length: Approximately 150 cm ■ It uses a buckle with a "quick-release mechanism," which is an absolute requirement for weight belts used for diving.