M-D 6304 Gray Vinyl Threshold Insert Low Threshold 36x1.375 in The M-D 6304 Gray Vinyl Threshold Insert is a durable, high-performance replacement seal designed for low-profile door bottoms with L-shaped or U-shaped channels. Made from resilient vinyl, it delivers a weather-tight barrier against drafts, moisture, dust, and insects while protecting the door base from wear and decay. Measuring 36 inches in length and 1-3/8 inches in height, it fits standard low-threshold doors up to 36 inches wide. The insert?s 2-inch base width ensures secure seating in the threshold groove, and its tool-free, adhesive-free installation allows for quick replacement of worn or damaged seals?restoring energy efficiency and comfort with minimal effort. Features - Durable vinyl construction resists water, dust, insects, and UV degradation - Creates an airtight seal to reduce energy loss and improve indoor comfort - Specifically engineered for M-D L-shaped and U-shaped low-threshold door bottoms - 1-3/8 inch height and 2-inch base width ensure stable, snug fit in standard channels - Easily trimmed with scissors or a utility knife for precise length adjustment - No adhesives, fasteners, or tools required?slides directly into existing door groove - Gray finish offers a clean, modern look that complements most door and trim styles - Superior to wood or foam alternatives?won?t rot, compress, or degrade over time - Ideal for residential entry doors, patio doors, and light commercial applications - Made in the United States for consistent quality and performance Specifications - Brand Name: M-D Building Products - Model Name: M-D 6304 - Part Number: 6304 - Product Type: Threshold Insert - Material: Vinyl - Color / Finish: Gray - Size / Capacity: 36 in L x 1.375 in H - Product Dimensions: 36 x 2 x 1.375 in - Item Weight: Not specified - Application: Low Threshold Doors - Compatible Door Bottom Types: L-shaped and U-shaped channels - Self-Adhesive: No - Hardware Included: No - Packaging Type: Bagged - Country of Origin: United States - UPC: 043197630456 - Global Trade Identification Number: 00043197630456 - Manufacturer: M-D Building Products Product Application This threshold insert is used by homeowners and maintenance professionals to renew the bottom seal on pre-hung exterior or interior doors featuring shallow, channel-style thresholds?common in older homes, condos, and multi-family dwellings. It?s especially effective on doors where original seals have hardened, cracked, or fallen out, compromising weather resistance. By restoring a continuous barrier at the door base, it helps maintain consistent indoor temperatures, reduces HVAC strain, and blocks allergens, pests, and light rain intrusion. Its compatibility with standard M-D low-profile door systems and straightforward slide-in installation make it a go-to solution for seasonal weatherization, rental property upkeep, or quick home efficiency upgrades?delivering lasting protection without altering hardware or flooring.