The Triangle Machine + (Plus) comes from a collaboration between Billy Miller, and Neil Grover of Grover Pro Percussion. Beater angle adjusts from 90 degrees, for a focused sound (ideal for pit work) to 135 degrees, for creating a nice spread of overtones (great for orchestral and contemporary settings). The position of the beater slides, side to side, to find the optimal beater balance for your particular setup. Includes the new custom made 5/16" Solid-Body Brass Beater. Length, weight, and balance (fulcrum) all optimized to get a great sound from your triangle. Mount, triangle, not included. 90 to 135 Beater angle adjusts from 90 degrees to 135 degrees. 90° is great for a more focused sound - ideal for pit work. 135° gives you a nice spread of overtones - great for orchestral, and contemporary settings. Side to Side The solid-body brass beater slides, side to side, to find the optimal position for your particular setup. Most helpful when the Machine is set to 135 degrees. Place It Anywhere Set it and forget it. Use any 3/8" percussion mount to place your Miller Machine anywhere, in any setup. Striking Surface Includes custom-made red latex striking surface. Natural Feel Excellent Rebound Minimal Stick Attack Great Visibility in Low-Light Settings Be confident you'll always get a great triangle sound.