If not specified on your order, the eggcrate pattern may not have equal sized holes. Contact Grill Works for detailed information regarding this.
For applications in floors of any thickness, walls or ceilings, where maximum air flow is desired. The Insert Model has a self-rimming, eased lip 5/16" thick and 3/4" wide. Fluted dowels secure each web to the side rails and end pieces. Specify the exact opening size when ordering.