This Edger Blade is a black, metal blade which is sold individually and comes certified from the manufacturer. Installation is rated as "Easy" and requires a socket set and wrench set. This blade attaches to the drive shaft and is used for edging the grass around driveways and walkways. If this part becomes worn/fatigued/damaged (which may happen after hitting the pavement) you will notice an odd vibration and poor trimming, at which time the part should be replaced.