It is typical to see a sliver of light visible on the sides of a brand new VForce4 assembly. This is unavoidable due to the design which incorporates a concave surface that preloads the reed tip. The VForce4 also uses a curved petal which along with the concave reed cage surface further work to preload the reed tip. After use, this sliver of light typically disappears as the reeds break-in and become seated. This has absolutely zero impact on performance.