The Precision Smooth Polished (PSP) bass strings of the 850 series reduce ambient noises when shifting;Perfectly suited for recordings and when using Piezo pick-ups;Special wire wound and partially ground bass strings;PSP technology (PSP = Precision Smooth Polished);Made in Germany;Medium Tension ;E-1: 7,0kg/15.43lbs;H/B-2: 6,0kg/13.23lbs;G-3: 6,5kg/14.33lbs;D-4: 7,3kg/16.09bs;A-5: 7,1kg/15.65lbs;E-6: 7,5kg/16.53lbs;