Genuine Nissan (118108J102) PCV VALVE.  For Nissan Elgrand E51 Nissan 350Z and other VQ engine variants (please check part number)

This is a genuine Nissan part to fit the E51 (2.5 and 3.5) also 350Z Z33 NOW SUPPLIED WITH A NEW 'O' RING

Generally an easy consumable to replace on most Nissan engines including the 350Z, but alas NOT AS SIMPLE on the E51! 

These are the first port of call if you have an oil consumption issue as they can gunk up and block causing excessive oil use

On an E51 It is positioned on the rear of the drivers side cam cover and is not easily accessible without removal of scuttle, wipers, and other bits and bobs on the way to the bulkhead to even get to it so not a simple DIY task, it is ideally replaced if your thinking of replacing the spark plugs at the same time or vice versa as it will save a job later on.