Pro-Cart AT4

Pro-Cart AT4 — Premium All-Terrain Slab Cart with 1,200 lb Capacity and Quick-Release Clamping

The Pro-Cart AT4 is Omni Cubed's next evolution of the Pro-Cart line, engineered for contractors and stone fabrication crews who need to move full stone slabs, panels, and countertop pieces across demanding jobsite conditions including curbs, stairs, gravel, lawns, and other rough terrain. With a 1,200 lb load capacity and 9" closed-cell polyurethane all-terrain tires, the AT4 is built to reduce the physical burden on workers during heavy shop-to-site material transport. The cart features an upgraded Quick Release Speed Clamp with a 4.5" maximum opening, accommodating thicker materials, mitered pieces, and larger edge profiles. An included Folding Kit allows the caster rails to rotate beneath the support beam for compact storage and easier transport between jobs.

Technical Specifications

Pro-Cart AT4 vs. AT3 Comparison

Compared to the AT3, the AT4 delivers a significantly wider 4.5" clamp opening versus the AT3's 3" opening, making it the right choice for thicker slabs, mitered edges, and more complex material profiles. The AT4 also adds a quick-release clamping mechanism and an included folding kit — features not present on the AT3 — giving crews faster setup, easier adjustment, and more compact storage without sacrificing the same 1,200 lb load capacity.

Key Features & Benefits

Quick Release Speed Clamp with 4.5" Opening

The upgraded quick-release clamping mechanism allows for faster, easier adjustment without removing the clamp from the cart, reducing downtime during material handling. The 4.5" maximum opening accommodates thicker slabs, mitered pieces, and larger edge details that a standard clamp cannot grip securely.

9" Closed-Cell Polyurethane All-Terrain Tires

The flat-free, non-marking 9" closed-cell polyurethane tires are engineered to roll over curbs, stairs, gravel, lawns, and other rough terrain without damaging finished surfaces. Their larger diameter improves stability and control when navigating jobsite obstacles under heavy load.

Anodized Aluminum and Stainless Steel Construction

The anodized aluminum framework combined with machined billet aluminum handles and stainless steel clamp shafts delivers a corrosion-resistant, high-strength build that holds up to repeated heavy-duty use in demanding shop and jobsite environments. Zinc-plated steel hardware and radiused corners on all extrusions further extend service life and reduce snag points.

EPDM Rail Padding and Silicone End Caps

EPDM padding strips on the support rail and silicone caps on all contact points protect slab surfaces from scratching or chipping during transport. Grey non-marking clamping pads ensure finished stone faces are not marred when the clamps are tightened.

Included Folding Kit for Compact Storage

The folding kit allows the caster rails to rotate beneath the support beam, reducing the cart's footprint for storage in a shop or transport in a vehicle. Folded dimensions of 56-1/2" x 12" x 16" make it practical to store multiple units or fit the cart into tighter cargo spaces.

Adjustable Wheelbase

The adjustable wheelbase range allows crews to fine-tune the cart's stance for improved balance and control depending on slab size and terrain conditions. This adaptability helps maintain stability when moving large, cumbersome pieces through doorways or across uneven ground.

Common Applications

Shop-to-Site Stone Slab Transport

Move full stone slabs from fabrication shop to installation site, including loading and unloading from vehicles, without requiring multiple workers to carry material by hand.

Navigating Stairs and Curbs

The AT4 is designed to go up stairs and over curbs, allowing a crew to transport heavy slabs into buildings or across elevated thresholds that would otherwise require a lift or additional labor.

Rough Terrain and Outdoor Jobsites

The 9" all-terrain tires handle gravel, lawns, and uneven ground, making the AT4 suitable for outdoor residential and commercial jobsites where smooth pathways are not available.

Countertop and Panel Installation

Transport large countertop pieces and panels through standard doorways with up to 64 inches of material clearance, reducing the risk of damage during tight-space maneuvering.

Thicker Material and Mitered Edge Handling

The 4.5" clamp opening accommodates thicker slabs and mitered edge profiles that exceed the capacity of standard slab carts, expanding the range of materials a single cart can handle on a job.

Finished Surface Protection During Interior Moves

Non-marking rubber tires and silicone-capped contact points allow the AT4 to be used on finished floors without leaving marks or causing surface damage during interior installation work.

Compatible Materials

• Natural stone slabs (granite, marble, quartzite, travertine, limestone)
• Engineered quartz slabs
• Porcelain and large-format tile panels
• Countertop pieces and prefabricated sections
• Mitered edge and thicker-profile stone pieces (up to 4.5" clamp opening)
• Glass and other rigid panel materials within the 1,200 lb load capacity

Product Documents

• Pro-Cart Comparison Sheet (PDF)

Frequently Asked Questions

Q: What is the maximum clamp opening on the AT4?
A: The AT4's Quick Release Speed Clamp has a maximum opening of 4.5 inches (114.3 mm), which accommodates thicker slabs, mitered pieces, and larger edge profiles.

Q: How does the AT4 differ from the AT3?
A: The AT4 features a wider 4.5" clamp opening compared to the AT3's 3" opening, adds a quick-release clamping mechanism for faster adjustment, and includes a folding kit for compact storage — all at a higher price point. Both carts share the same 1,200 lb load capacity and all-terrain, flat-free, non-marking tire design.

Q: Does the AT4 include a folding kit?
A: Yes. The AT4 ships with one cart, two holding clamps, and one folding kit. The folding kit allows the caster rails to rotate beneath the support beam, reducing the folded footprint to 56-1/2" x 12" x 16" for easier storage and transport.

Q: Will the AT4 tires mark finished floors?
A: No. The 9" closed-cell polyurethane tires are flat-free and non-marking, and the clamping pads are grey non-marking rubber, making the cart safe to use on finished interior surfaces.

Q: Can the AT4 navigate stairs?
A: Yes. The AT4 is specifically designed to go up stairs as well as over curbs, gravel, lawns, and other rough terrain encountered on typical jobsites.

Q: How is the AT4 shipped?
A: The AT4 ships in two boxes — Box 1 at 35 lbs and Box 2 at 40 lbs — with a combined shipping weight of 75 lbs. All products ship within 3–5 business days.