CO2 inflators are bloody handy for when you need to inflate quickly, or don't want to carry a bigger hand pump around. Both options fit on Schrader and Presta valves and they also come with a neoprene sleeve which insulates your hand from the cold during usage. Both models have the ability to screw onto your CO2 cartridge without discharging it, useful for putting on your bike or in your bag.
The major difference between the two is that the Black model connects to your valve at right angles with your CO2 cartridge. The gold model sits straight in a line with it. The other difference is that the gold one looks quite bling!
Note: these comes without CO2 cartridges, we haven't figured out how to send them cheaply yet. CO2 cartridges are pretty easily obtained from your local bike shop :)