This is a set of 6 NGK BCPR6ES-11 spark plug which will fit your Datsun/Nissan 300ZX Z31 (Non-Turbo).
These come pre-gapped but you will want to make sure you double check the gaps with a spark plug gap gauge that can accommodate the gap range that fits your exact vehicle. For more information on gapping your spark plugs, as well as more information on how to replace them, check out our Z-car spark plug replacement guide.