The stiffness rating of an arrow shaft — a smaller number means stiffer. It has to match your draw weight and draw length, not your bow model.
An arrow doesn't leave the bow rigid, it bends: on release the nock end accelerates faster than the point, and the shaft snakes its way around the riser. If its stiffness doesn't suit that, no sight on earth compensates for it permanently. The distinction that matters isn't printed on the shaft: the printed static spine is a lab value, while dynamic spine only emerges from your draw weight, your arrow length and your point weight — two archers with identical arrows experience different stiffness. Manufacturer charts therefore start beginners on softer, higher spine numbers. And a safety point that gets said far too rarely: a shaft that is much too weak for your draw weight can be overloaded on release and break at the riser — not even 'just to test it'.