A trace spring does a number of things to mitigate problems on a camping trip. Firstly, one of these added to your guy ropes reduces the instance of damage to any shelter during high winds by allowing the guy ropes to move with the wind.
Secondly, the tension in the spring ensures your guy ropes return to their taught state and maintain tension on your shelter after high winds as well as allowing for any stretch or shrinkage of tent fabric as it wets and dries out.
These are particularly useful on long stay camping trips where you want to set up our shelter and not have to worry about making adjustments throughout the day (or night). They are suited to standard tent pegs and come in three different strengths to suit all shelter types.