Sonic Sports, Inc. Sonic Inline Hockey Puck STABLE - Perfectly balanced puck body & low profile runners for flatter play FAST - Low-friction runners boost speed & cut drag - 6 Power Grooves accelerate the puck off your blade & improve rebound off the boards TOUGH - One-piece runner system wont fall out after a hard slapshot PURE - Made with high-impact virgin polymers VERSATILE - Ideal for indoor & smooth outdoor surfaces (Sport Court, Ice Court, smooth concrete, smooth wood) NOT RECOMMENDED for rough concrete and asphalt surfaces (driveways, parking lots, streets)