Taylor Made RAC CGB. RAC stands for Relative Amplitude Coefficient, a technology TaylorMade developed to improve shot-making and characterised by 'Feel Pockets' in the back of the club head. The CGBs - which stands for 'Centre of Gravity Back' - are TaylorMade's most expensive set of irons - the company describe them as 'a premium product at a premium price'. The heads feature a low and deep centre of gravity which Taylor Made claim makes possible a rare combination of distance, control and forgiveness The Performance Cartridge comprises tungsten-loaded, high-density urethane and five metal inset rods which are precisely positioned to centre weight in the clubhead, promoting greater power while making them extremely easy to hit. Very easy-hitting clubs aimed at higher handicappers with deep pockets.