External 1TB Portable Hard Drive Shockproof Durable Metal Casing for PC & Mac

Summary

• Light Material: Made of silicone and PA66 material, which is light weight, easy to carry, durable, can be used for a long time.
• Easy to Use: The knocker ball is easy to hold and use in underwater situation and environment, increase the possibility of being helped in special condition.
• Using Method: Put it on a diving cylinder, pull the strap in the water, and when you let go, the ball will hit the tank with a loud sound, making you easier to be heared by your partner or others.
• High Elasticity: Strap part has high elasticity, that the hitting ball can be used on most cylinders of different sizes.
• Much Louder: Set on your diving cylinder, pull the ball, it makes a much louder sound than other diving equipment, practical diving accessories.