The N-8400 SD is an alternative needle (replacement needle) that performs identical to the OEM needles that are made by the manufacturer for YAMAHA record cartridges. This replacement needle is a "synthetic diamond needle" type. This is a generic model that plays a regular range of sound ranges, with a standard conical shape. General life is about 200 hours. The successor to the Y.60-84 N-8400 TR.BLU (4951586452201).