A relative newcomer in the cello string world are the Perpetual strings from Pirastro. The strings have a very clear and powerful sound. Every string plays very easily, especially the G and C strings, even with very light bowing techniques. The G and C strings are also available in the strong version with a higher string tension.
The A and D strings are made of steel, wound with chrome steel, the G and C strings have a multi-wire steel core, with tungsten winding. See table below.
Perpetual cello strings are also available in the versions Edition/Cadenza en Soloist.
Click here for the datasheet of Pirastro Perpetual cello strings.