The Traditional series (520 series) are generally referred to as the "White Card (low tension)", "Red Card (high tension)", and "Yellow Card (very high tension). The basses are warm and strong. The trebles are rectified for consistent diameter end to end for good intonation. They are easily controlled, are secure under the fingers, and like the basses have a strong, clear tone with a sweeter edge. The "P" series have nylon wound trebles.
