Shame it's not 100% correct though, "Cylinder Testing
Compressed air cylinders MUST be tested regularly in accordance with UKPSF guidelines. If your compressed air cylinder is fibre wrapped, it must be tested five years after manufacture. This also applies to CO2 bottles and indeed to all bottles that have a capacity of over half a litre". According to the UKPSF aluminium bottles have a 10 year test period, not 5 years as you suggest.