MRCOOL MLG450 line guard kits are complete, ready-to-install systems designed specifically for MRCOOL mini split installations. These kits include duct sections and common fittings needed for standard runs, making them ideal for DIY homeowners and straightforward installations.

Best for:

• MRCOOL single-zone mini splits
  
• MRCOOL multi-zone systems
  
• Standard exterior wall routing

RectorSeal Fortress 4.5" line set covers offer a modular, professional-grade system with the widest selection of fittings and routing options. Fortress components are fully compatible with MRCOOL MLG450 systems, making them ideal for expanding or customizing your installation.

Best for:

• Complex routing layouts
  
• Multi-directional transitions
  
• Central ducted heat pump systems
  
• Installers who need maximum flexibility

RectorSeal Cover Guard™ is a premium, adjustable line set cover system designed for installers who want maximum durability, flexibility, and a cleaner finished appearance.

Unlike standard snap-together systems, Cover Guard features a patented multi-stage adjustable duct design that expands to accommodate multi-zone line sets. It maintains the same internal capacity as traditional 4.5" systems, but with a tighter, more refined profile that hugs the wall for a sleek finish.

Key advantages of Cover Guard include:

• Patented adjustable design for single-zone and multi-zone systems
  
• Interior locking tabs for secure snap-in installation
  
• ¼-turn plastic cam screws that resist rust and over-torque damage
  
• Pre-installed sliding zip-tie clips for clean cable management
  
• Flat-bottom channel and elbows designed to help deter pests and nesting
  
• UV- and weather-resistant construction built for long-term durability
  

Choose Cover Guard when:

• Installing multi-zone mini splits
  
• You want built-in adjustability
  
• The installation is highly visible
  
• You want premium hardware and a cleaner finished look
  

Fortress offers modular routing flexibility. MRCOOL kits provide convenience. Cover Guard delivers engineered, adjustable performance for installers who want the highest-end solution.

Choose MRCOOL Line Guard Kits for convenience and standard installations.

Choose Fortress 4.5" if you need modular routing flexibility and additional fitting options.

Choose Cover Guard™ if you want premium adjustability, tighter wall fitment, and engineered hardware for high-visibility or multi-zone installations.

The MRCOOL® MLG450 Line Guard Kit is designed to cover up to 12 feet of ductless mini split refrigerant lines.

Each kit includes:

• Three straight duct sections (4 ft each – total 12 ft)
  
• One 90° bend
  
• One wall opening cover
  
• Interconnecting pieces
  

The system is lightweight, flexible, and easy to install. If your installation requires additional coverage, multiple MLG450 kits can be connected together to extend the total run length.

Available Colors:

• White (MLG450)
  
• Tan (MLG450-T)
  
• Gray (MLG450-G)
  

This makes MRCOOL kits ideal for standard mini split installations where convenience and simplicity are the priority.

The RectorSeal Fortress® 4.5" (LD122) system is a complete modular line set cover system designed for mini-splits, high-velocity systems, and conventional ducted HVAC systems

Available components include:

• 7.5 ft duct sections (longer lengths reduce joints and waste)
• Couplers
• 45° and 90° flat elbows
• Inside and outside vertical elbows
• Adjustable 45–90° fittings
• Sweep elbows
• Tees
• Wall inlets
• Wall flanges
• Soffit inlets
• Flexible elbows
• Flexible adapters
• End fittings
• Reducers
• Twist-lock duct clips
• Complete LDK wall duct kits

Unlike all-in-one kits, Fortress allows you to fully customize routing for complex installations, central ducted systems, or multi-zone mini splits.

MRCOOL MLG450 line guard kits and RectorSeal Fortress 4.5" (LD122) components are compatible and can be used together. Fortress fittings can expand or customize a standard MRCOOL 4.5" kit installation.

RectorSeal Cover Guard™ is a separate adjustable system and is not interchangeable with standard 4.5" Fortress or MRCOOL components. Cover Guard fittings are designed specifically for the Cover Guard duct system.

If you plan to mix components, ensure you are staying within the same product family (4.5" MRCOOL/Fortress or Cover Guard).

We stock the following for fast shipping:

• MRCOOL MLG450 Line Guard Kits (White, Tan & Gray)
  
• RectorSeal Fortress 4.5" (LD122) Components (White & Gray)
  
• RectorSeal Cover Guard™ Standard Kits & Components (White & Gray)
  

Orders for stocked colors typically ship quickly from our warehouse.

Fortress 7.5-foot duct sections are classified as oversize by shipping carriers due to their length.

Long duct pieces require:

• Special packaging
  
• Dimensional weight pricing
  
• Oversize carrier handling
  

Even though they are lightweight, carriers charge based on size rather than weight for these items. This results in an oversize shipping fee on 7.5 ft sections.

In most cases:

• Stocked items ship from our warehouse.
  
• Drop-ship colors may ship separately.
  
• Oversize duct sections may ship in separate cartons.
  

Tracking information will be provided for each shipment if multiple packages are required.