Callaway is only offering a limited number of these tricked out drivers to each territory and I bought them all. First batch arrived yesterday and this is the prototype model that Phil has been hitting this year. Offered in 9.5-degrees only, the Sub Zero features a more compact, 440cc clubhead and the lowest CG of any Callaway driver to date. This is the spin-killer from Callaway and features a very lightweight Carbon Triax crown that allows more weight to be distributed low in the clubhead while two interchangeable sole weights (10g and 2g) allow for custom tuning of launch angle and spin rates. With the heavier weight in the forward position the Sub Zero produces a lower trajectory with less spin and conversely offers more forgiveness and a higher trajectory with the heavy weight in the rear position.