Double K 70cm Freediving Buoy $169 The Double K Freediving Buoy The Double K Freediving Buoy is probably one of the best engineered, thought over and well designed buoys out there. The buoy meets all the standards, qualifications and requirements for a perfect buoy professionally made for freedivers by freedivers. The Double K 70cm Freediving buoy is made out of polyester fabric coated canvas, and the bottom is made out of mesh to allow the water to flow freely. The straps are made out of PES, and the buoy has two quality plastic YKK zippers, and Velcro for easy access and durability. The Double K freediving buoy is one of the best freediving buoys you’ll come around!