I am selling this item to organize my equipment. Seymour Duncan STK-S4m Classic Stack Plus [STK-S4m (Middle) is "center reverse (RW/RP) specification."] Functionality has been confirmed, and there are no issues with normal use. There is a general feeling of use. Please refer to the photos. It is slightly thicker than a standard single pickup [such as SSL-1], but I had it installed on my Squier Vintage Modified Stratocaster, and it fit without any problems. Includes the main unit, the original pickup cover, and screws. No other accessories are included. Please understand that this is a used item, and only those who can accept this are welcome to purchase. Features The STK-S4 has a bottom coil for noise cancellation, allowing it to output traditional Strat sound without noise. The middle position model is reverse wound/reverse polarity, so hum cancellation is achieved in half-tone positions even when coil-split. Specifications ■ Guitar Pickup ■ For Stratocaster ■ Middle ■ White ■ Magnet: Alnico 5 ■ DC Resistance: 8.6k rwrp