The DiveAlert SMB (surface marker buoy) features Closed-Circuit (one-way valve) construction, which prevents air spill at surface. Inflate on the surface to attract visual attention or redundant flotation. Inflate at depth to send up as a surface marker. Solas reflective tape (Coast Guard approved) across top of SMBcreates better visibility day and night. Over-Pressure Valve (OPV) prevents bursting and easy air dumping. Deluxe SMB is 65" long by 8" wide (165 x 20 cm) which provides approximately 40 lbs. (18.1 kg) of lift. Nylon strap handle on top allows for easy attachment of light or slate. 400 denier poly-urethane coated nylon material, this SMB will last dive after dive without issue. In addition the Deluxe Version has Safety Orange one side and Florescent Lime/Yellow the other side, a filler nozzle for both oral and BC LP hose inflation with a small pocket that will accommodate a finger spool.