Original Replacement Sea-Doo, Yamaha and Nautica Underwater Sea Scooter Batteries. 

Only original replacement batteries include a proprietary catalyzing system specifically designed for safe use in Sea-Doo, Yamaha, and Nautica Sea Scooters. 

Beware of after market "knock off" batteries that proliferate online. They do not include the safety equipment required for use in a watertight compartment and may explode in sea scooters.