The reference string for double bass flexible multi-wire spiral core for long period of musical vibration and low inertia Ideal for playing bow or pizzicato Solo Agreement. 3/4 size for 1040-1060mm (41-41.7 ") scale The: Average tension 32.0kg / 70.5lbs Mid: Average tension 33.0kg / 72.8lbs Si: Average tension 33.0kg / 72.8lbs Fa #: Average tension 33.0kg / 72.8lbs Do #: Average tension 34.0kg / 75.0lbs Set Medium tension 131.0kg / 288.9lbs