Your squash racket strings choice will depend on your level of play and the sensation you are looking for when playing squash.
FOR REGULAR PLAYERS

Regular players need durability but most of all power - which comes mainly from the strings and their ability to transfer energy upon impact. Such players will therefore need a thick gauge string of more than 1.25 mm.
FOR INTENSIVE PLAYERS

Intensive players will need three key strengths: precision - implying the ability of the strings to apply effects onto the ball, and the power and durability of the strings over time. In order to meet those criteria, a fine gauge of less than 1.25 mm is advised.
CHECK OUR SQUASH RACKET STRINGS RANGE