Captain O-Ring HPA / CO2 Burst Disk 1.8k - 2 pack (Compressed Air Paintball) [Bonus CO Microfiber Cloth] 1.8k burst disk (2 burst disks included) Used on CO2 tanks and as the low pressure burst disk for 3000psi and 4500psi compressed air tank regulators Includes a bonus Captain O-Ring Microfiber Cloth! Manufactured and warrantied by Captain O-Ring LLC