XDeep Open Simple DSMB 140cm - Inflatable Safety Marker Buoy for Scuba Diving & Snorkeling | High Visibility Diving Signal Tube for Underwater Safety & Emergency Use

No dump valve as the air can expand out of the end of the tube. Make sure to keep an eye on tension on the bouy to keep it upright and avoid air spilling out.

The handy small plastic tube on the top side of the SMB offers a place for your glow stick, while the 3M reflective stripe makes the DSMB recognisable even at night.