Seymour Duncan SH-4, JB Model Humbucker, Any Position, Black. For nearly four decades, the legendary JB Model (SH-4, TB-4) has been the ultimate hot-rodded humbucker. A truly modern classic! Twin Town Guitars does guitar repairs on instruments, electronics, and Plek work. We install pickups! • MFSKU 11102-13-B • UPC 800315001057