This genuine OEM sourced replacement part is designed for use with blowers/trimmers. This is the spring for the spark plug boot. This spring is made out of metal and it is sold individually.

This spark plug boot is an authentic OEM supplied replacement part, not an aftermarket equivalent. This rubber cap helps is used to connect the spark plug to the armature-magneto. Over time rubber material can dry out and crack requiring replacement. Please note, this part is sold individually.