This is the Spearmaster High Pressure Spearfishing Dive Signal Marker Buoy SMB Floats Features: 20 PSI pressure means more flotation at depth Valve positioned so it won't catch on other floatlines Front and rear D-rings for connecting to float lines Nylon ultra-strong yet light material for longevity and durability Perfect for yellowtail, wahoo, ambejack, tuna, and marlin 15 Liter: 28 long x 26" diameter The Spearmaster High-Pressure Float is a formidable tool in your arsenal of spearfishing equipment. This high-pressure float is capable of achieving over 39 pounds of lift to a depth of 45 feet with 20 PSI. The float is constructed of the same nylon-reinforced material that is used in the construction of the world-famous Zodiac boats allowing for spearfishing aficionados to maintain full buoyancy and peace of mind. Zodiac uses this ultra-strong yet light material for longevity, durability, and dependability on the high seas. A spearfishing float should have all these qualities to help you land that prized fish, whether it is a yellowtail, wahoo, amberjacks, tuna, etc. This heavy-duty float has been tested to withstand up to 20 PSI. These floats are ideal for any corner of the world. This float will be sure to give your fish a fight and help you get that fish on the boat."