This is a transplant of KOSS KSC75 drivers into metal housings widely used overseas for Grado driver modifications. Both are new. Regarding the KSC75, the original parts from which the drivers were removed will also be included, as it is possible to restore them to their original state if desired. The current price is set below cost as a test bed. Therefore, please refrain from price negotiations. As you know, the KSC75 is a classic model from KOSS, renowned for its attractive bass and high cost-performance sound quality. However, the ear hook style is a matter of preference, and there is a tendency for the bass to escape, so there are many examples overseas of transplanting them into Porta Pros or incorporating them into other modification housings. The drivers themselves are highly complete, and the sound characteristics change significantly depending on the housing, making them very popular for modification purposes. The metal housing used is a product widely used overseas for Grado, with a durable open-back structure. The ear pad size is the same as Grado, so they are compatible. Currently, S-pads are installed. The cable uses the most versatile dual 3.5mm type. Because of its high sensitivity and ease of driving, it does not require a specific source device, and you can fully enjoy the original sound even when directly connected to a smartphone. A new HIFIMAN genuine stock cable is included. The sound tendency is the basic warm and powerful tone of the KSC75, with the addition of the thickness of the mid-low range, spatial expression, and metallic, sharp edges provided by the metal housing, resulting in a so-called "don-shari" and enjoyable sound. Please note that it is not a monitor-oriented sound. If you have any other questions, please feel free to ask in the comments. ===================== ・Returns and cancellations are not accepted. ・Bulk purchases, dedicated listings, and various event support are possible (category changes, re-listing, etc.). ・Since it is also listed elsewhere, there is a possibility that the product will be deleted without notice once it is sold out. #KOSS #KSC75 #grado #SR325x #mod