If you have a SIG SAUER MCX or MPX air rifle, this high pressure aluminum tank sounds like a great idea.  It comes in three parts; the tank, a buttplate and a C02 adaptor.  You also have a gauge to help you check the amount of air left in the tank and a regulator to controls the pressure of air delivered to your gun allowing you to enjoy more efficient shooting.  Equipped with a foster quick release fill adapter, you'll enjoy quick and easy filling from a hand pump, aluminum scuba tank, or carbon fiber tank. 

Features:

• Air Venturi 13 Oz Aluminum HPA Tank
• Regulated to 1,100 psi
• Max fill is 3,000 psi
• Fill directly from a high pressure pump or tank via standard foster quick fill adapter
• Integrated pressure gauge
• Two ASTM compliant burst disks
• Buttstock
• CO2 adapter
• Shoot hundreds of rounds before refilling
• 2" diameter
• 10" long
• Includes: buttstock, CO2 adapter