NDS 241-1 Spee-D Channel Drain Grate, Gray Spee-D channel is ideal for commercial as well as residential applications Custom accessories make for fast and easy installation Ideal for driveways, decks and commercial areas Flanges provide straight installment; Grate Opening:3/8 inch x 3 1/4 inch. Product dimensions (L X W): 24 x 4-1/8 inches Plastic material is chemically resistant, rust proof and maintenance free