M-D Building Products 11619 M-D Heavy Duty Fluted Saddle Threshold, 36 in L X 6 in W X 1/2 in H, Aluminum, quot, Unfinished All-season protection against drafts, moisture, dust and insects Heavy duty aluminum for long lasting seal and durability Meets code for wheelchair access Seals gaps up to 1/2-Inch high Save energy and money year-round