This is the Hollis Compact Orange Closed-Cell Signal Marker Buoy SMB for Scuba Divers Features: Great Safety Devise Used by Serious Divers Carry on Every-Dive Smart-Way for Diver to Mark Location Great for Safety Stops, Decompression-Stops and Signaling the Boat Bright-Orange for Easy Recognition Closed Cell Design Durable 300-D Polyester with Radio Frequency (RF) Welded Seams Oral Inflation and Quick Dump Valve Sturdy Nylon Webbing Strap Loop with Stainless Steel D-Ring Wrist Lanyard for Hand-Held Use The Hollis Signal Marker Buoy (SMB) is a great Safety Devise that all Serious Divers carry on Every-Dive. The SMB is the Smart-Way for a Diver to Mark their Location when making Safety Stops.