Fat-Beams are compression wound to produce fat mids, bright highs and that distinct edgy Fat-Beam sound. Hand-made with the finest American stainless steel available, wound on round cores for increased flexibility and tone. DR Strings are hand-made (not machine-made) because our expert string-makers are capable of making micro adjustments needed through the winding process for the best sound and feel possible. The Dif, ference is Real. Material: Stainless Steel. Round Core Wire with , Ball End. Gauges: 45, 65, 85, 105, 125.