2-3 Weeks. 45 Day Lowest Price - 100% Satisfaction Guarantee. CornerFills are long, thin rods of flat-cut Studiofoam that are beneficial in two ways. Acoustically, they smooth out excess low frequency energy that congregates in room corners. Aesthetically, they give you smooth, clean edges to butt your Studiofoam, SonoMatt and Venus Bass Traps up to for a more professional appearance. Highly recommended!