Rises to a height of up to 500' and burns for up to seven seconds at 16,000 candela.Using aerial signals: Aerial flares should be fired after sighting or hearing a potential rescue vessel. To attract attention to your distress situation, the U.S. Coast Guard recommends that you fire two aerial flares--one immediately after the other--so rescuers can confirm the sighting and the direction of the signal.These flares replace all previous Orion 12-gauge signals with improved performance. They will fit any 12-gauge launcher manufactured since 1981. Four-pack. Signal Type: 12-gauge aerial flare Light Output: 16,000 candela Burn Time: Up to seven seconds Average Altitude: Up to 500' Deployment Method: 12-gauge launcher Type Approval: USCG Day/Night Replacement Interval: 42 months from manufacture date How Sold: Four pack