The Hercules DG200B Smartphone Holder is the best tool when practicing with apps such as tuners, metronomes, effects, or for looking up lyrics on the gig. The Smartphone Holder fits devices with a width of 50mm-90mm (2"-3.5") and adjusts a full 360° easily. The holder fits round tubes 15.8 mm - 25.4 mm (0.62" - 1") and square tubes of 19 mm (0.75").