The Greek long-necked bouzouki, is a bowl-backed lute with either 3 or 4 double courses of metal strings tuned d'd'/aa/dd or d'd'/aa/ff'/cc'. 8-String Set (4 Courses) Plain Steel; Stainless Steel Round Wound Loop-Ends String gauges: .010p -.010p, .013p - .013p, .021w-.010p, .031w-.013p Made in the USA with American Wire