Pemko 171A36 5" x 1/2" Mill Finish Aluminum Saddle Threshold 36" Long. Fluted top extruded aluminum threshold manufactured from 6063-T6 tempered aluminum. Designed for use in exterior or interior openings. Suitable for commercial or residential use. Threshold top is pre-drilled with mounting holes. All Pemko thresholds are shipped over-length to allow for exact sizing. Actual length is 36-1/2".