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. Size 1/2 for scale up to 9 65mm (38 ") The: Average tension 25.5kg / 56.2lbs Mid: Average tension 27.5kg / 60.6lbs Si: Average tension 28.5kg / 62.8lbs Fa #: Average tension 29.5kg / 65.0lbs Set Medium tension 111.0kg / 244.6lbs