When your CPV O-ring fails it causes a slow oil leak on the passenger side of the engine, before the only way to fix this was to replace the CPV itself, but now you can replace the o-ring at a fraction of the cost to fix your oil leak.
The CPV itself is generally not the cause of the issue - it is the O-ring that over time fails from heat cycling and oil exposure due to the Buna rubber used in OEM o-rings, while this new Viton Fluoroelastomer is resistant to a much higher temperature to ensure prolonged life without leaking.
