These came of my car at 98,500 miles. The plastic guides had failed and I opted to replace the whole unit on each side for long-term preventative maintenance. These are now perfectly functioning with new guides just put on, and could certainly last another 100k miles or more. If for some reason the internals of your cam adjusters fail these would be a great replacement at substantial savings over new. Typically it's just the plastic feet/pads that fail though, and occasionally the electronics within these cam adjusters fail, but the hydraulic units themselves are very solid. Selling for $475 for the pair plus shipping. New they are ~$1,500 for the pair OEM.