The HERCULES Guitar Stand GS412B PLUS features the upgraded Auto Grip System (AGS) yoke, Instant Height Adjustment Clutch, Specially Formulated Foam (SFF) rubber contacts and the adjustable back rest. Features The built-in Auto Grip System safely locks the instrument in place. The Upgraded AGS yoke is designed to accommodate more guitar neck sizes from 40 mm 52 mm (1.57 - 2.05) including classic, acoustic, electric and bass guitars. The attached NINA (Narrow Instrument Neck Adjustment) are specially designed to increase the thickness of