The ST-15GD SD is an alternative needle (replacement needle) that does not have the OEM needle produced by the manufacturer for use with Sanyo (OTTO) 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 S.38-15GD ST-15GD SMK (4951586361107).