The Dye Core air tank is a composite bottle with a stainless steel core.
Still it is light, small and Pi approved. 
The Volume of this bottle is 1.1 liters (68ci) with 4500 psi (300 bar)
It comes without a regulator.

Technical details

• Weight: 0,8 kg
• Pressure: 300 bar
• Length: 197 mm
• Durchmesser: 111 mm
• Lifetime: 10 years (extendable twice for 5 years)