Mr Glass

MG-300 Horizontal Sliding Window

Aluminum impact horizontal slider up to 127 by 74 inches for wide-format installations. Dual LMI+SMI at 140 psf positive and negative.

Impact Rating LMI/SMI Design Pressure +140/-140 psf Energy Florida Made in Florida

Impact protection, built for South Florida

The MG-300 is Mr Glass's impact-resistant horizontal sliding window, opening side-to-side on tracks for wider openings than a single-hung configuration supports. Sizes up to 127 by 74 inches, dual LMI and SMI impact-rated for HVHZ installations, rated to 140 psf design pressure.

  • Florida Building Code product-approved
  • impact-rated laminated glass
  • Energy-efficient Low-E insulated glass options to control heat gain
  • Professionally installed across South Florida by Armor Pro
Configurations X = operable panel (it opens) · O = fixed panel (doesn’t open). Panels read left‑to‑right as viewed from outside (hung windows read top‑to‑bottom). Example: XO = operable on the left, fixed on the right.
Horizontal Roller (OX)
Horizontal Roller (XO)
Horizontal Roller (XX)
Horizontal Roller (OXO)
Horizontal Roller (XOX)
Horizontal Roller (OXXO)
Impact Protection
Tested to withstand hurricane wind-borne debris
Engineered Strength
Built and tested to Florida product-approval standards
Energy Efficient
Low-E insulated glass options reduce heat gain
Limited Warranty
Manufacturer warranty plus Armor Pro install workmanship

At a Glance

Max Size 127.625 x 74 in
Design Pressure +140/-140 psf
Impact Rating LMI/SMI

Sizes & Pressures

Configuration Max size Design pressure
Impact Resistant Horizontal Sliding Window 127.625 x 74 in +140/-140 psf

Glass & Energy Performance

Glass packageU-FactorSHGC VT
5/16" Laminated Clear: 1/8" Clear HS + 0.09 PVB + 1/8" Clear HS1.1380.596 0.649
5/16" Laminated Clear w/ SB70: 1/8" Clear HS (SB70 surf#2) + 0.09 PVB + 1/8" Clear HS1.120.273 0.447
5/16" Laminated Gray: 1/8" Gray HS + 0.09 PVB + 1/8" Clear HS1.1190.48 0.437
5/16" Laminated Solex Green: 1/8" Solex Green HS + 0.09 PVB + 1/8" Clear HS1.1230.491 0.586
7/16" Laminated Clear: 3/16" Clear HS + 0.09 PVB + 3/16" Clear HS1.1160.58 0.645
7/16" Laminated Clear w/ SB70: 3/16" Clear HS (SB70 surf#2) + 0.09 PVB + 3/16" Clear HS1.1150.279 0.439
7/16" Laminated Gray: 3/16" Gray HS + 0.09 PVB + 3/16" Clear HS1.1090.434 0.363
11/16" Insul-Laminated Clear w/ SB70: 1/8" Clear FT (SB70 #2) + 1/4" Air + 1/8" Clear HS + 0.09 PVB + 1/8" Clear HS0.7250.203 0.321
7/16" Laminated Gray: 3/16" Gray HS + 0.09 PVB + 3/16" Gray HS1.0270.356 0.2
11/16" Insul Lam. Gray w/ SB70: 1/8" Gray + 1/4" Air + 1/8" Clear HS (SB70 #4) + 0.09 PVB + 1/8" Clear HS0.7840.248 0.263
11/16" Insul Lam. Gray w/ SB70 & white interlayer: 1/8" Gray + 1/4" Air + 1/8" Clear HS (SB70 #4) + 0.09 white PVB + 1/8" Clear HS0.7910.233 0.236
13/16" Insul-Laminated Clear w/ SB70: 1/8" SB70 Clear + 1/4" Air + 3/16" Clear + 0.60 PVB + 3/16" Clear0.7150.225 0.451

Performance Certifications

Florida Building Code Product Approval

Energy-performance data on file (manufacturer-published; not third-party certified).

  • FL DBPR FL20359.R5

Options

Glass tint
Clear (standard)GrayBronzeSolex GreenSolargrayLow-E (Solarban SB70 / SB70XL / SB60)Privacy (white / translucent interlayer)

Ready to install the MG-300 Horizontal Sliding Window?

Armor Pro measures, permits, and installs it across South Florida — code-compliant and warrantied. Get a free, no-obligation estimate.

Frequently Asked Questions

The MG-300 is Mr Glass's impact-resistant horizontal slider that opens side-to-side on tracks, which lets it span wider openings than a single-hung window can. We install it where you want a wide-format window, and it comes in configurations from a simple two-panel OX or XO up to multi-panel OXO, XOX, and OXXO layouts. It's a strong pick for wide South Florida openings that still need full impact protection.

Yes. The MG-300 is dual LMI and SMI impact-rated and HVHZ-approved, so we can install it in Miami-Dade and Broward's High-Velocity Hurricane Zone. It carries Florida Product Approval FL20359.R5 and is rated to 140 psf design pressure. We'll verify the current approval covers your exact size and configuration at quote.

The MG-300 is sized up to roughly 127.625 inches wide by 74 inches tall in its widest impact-resistant configuration, rated to +140/140 psf design pressure. That width is why it's used for wide-format openings instead of a single-hung. We confirm the maximum size your wall and configuration will support during the site measure.

The most efficient MG-300 packages are the insulated-laminated options with Solarban SB70 Low-E. For example, the 11/16" Insul-Laminated Clear with SB70 reaches a U-factor of 0.725 and SHGC of 0.203, and the 13/16" Insul-Laminated Clear with SB70 reaches U 0.715 / SHGC 0.225. By comparison, the basic 5/16" Laminated Clear is U 1.138 / SHGC 0.596, so the insulated SB70 builds cut heat gain substantially. We'll help you weigh energy performance against budget at quote.

Glass tint options on the MG-300 include Clear (standard), Gray, Bronze, Solex Green, Solargray, Low-E (Solarban SB70 / SB70XL / SB60), and Privacy with a white or translucent interlayer. Tinted laminated builds like Gray and Solex Green lower the SHGC versus clear, with the 5/16" Laminated Gray at SHGC 0.48 and Solex Green at 0.491. The aluminum frame comes standard with an AAMA 2604 powder coat (5-year warranty) and upgrades to AAMA 2605 (10-year warranty).

Installed pricing on the MG-300 depends on the overall size up to about 127 inches wide, how many panels the configuration uses (OX, XOX, OXXO, and so on), the glass package you select, and the condition of the opening. An insulated SB70 Low-E build costs more than a basic laminated clear package. Armor Pro provides a free estimate so you get an accurate price for your wide-format opening.

Mr Glass runs a deep catalog, and we install across most of it. On the residential side that means impact windows in single-hung, horizontal-roller (sliding), fixed picture, and casement and awning styles, plus a full range of doors: entry and outswing doors, architectural pivot doors, and sliding glass doors including the multitrack pocket slider. They also build a commercial line of impact and non-impact storefronts, window walls, curtain walls, glass railings, and aluminum louvers that we handle on light-commercial projects. We help you match the right Mr Glass product to each opening and pull the matching approval for your county.

Most of the line is, but it depends on the specific product. Mr Glass's premium residential windows are dual-certified to both Large Missile Impact (LMI) and Small Missile Impact (SMI), which covers them for high-rise and coastal work anywhere in the High-Velocity Hurricane Zone of Miami-Dade and Broward. Their value-tier windows and all of their doors carry the impact certification needed for the HVHZ as well, and a couple of commercial products (the MG-275 door and MG-4500 storefront) are non-impact and are not used in the wind-borne-debris zone. We confirm the exact product, rating, and approval for your address before we quote and permit.

A horizontal roller opens side-to-side on a track instead of up and down. It is a practical choice for wide openings, over kitchen sinks, and anywhere a vertical sash is awkward, and it gives a large clear view with an easy one-hand operation.

Protect your home with Armor Pro Windows & Doors!

Call (954) 231-7164 or Get Started Online with a Free Estimate!