ROBLOCK Trailer Jack Block 6"H RV Stabilizer Block — 11.5" Square, Stackable, 40,000 lb Capacity with Bag

ROBLOCK 6"H Trailer Jack Block is a heavy-duty, stackable RV stabilizer block that supports up to 40,000 lbs and helps eliminate movement under tongue jacks, 5th wheels, scissor stabilizers and more.

When you park a trailer or camper, a stable base beneath jacks and stabilizers prevents rocking, uneven settling and damaged jack feet. The ROBLOCK jack block is engineered from a reinforced polymer with UV-resistant additives so it stays rugged through repeated outdoor use. Each block measures roughly 6 inches tall and 11.5 by 11.5 inches across, stacks securely for adjustable height, and includes a convenient storage bag and carrying rope for easy transport and organization.

How does this block stop sway and movement when my trailer is parked?

The block creates a broad, non-slip platform that spreads load and prevents jack feet from digging into soft ground. Its textured top and sturdy polymer construction reduce lateral shift and minimize the bounce from footsteps or wind.

• Wide 11.5" × 11.5" footprint for load distribution
• Textured contact surface prevents sliding
• High-performance polymer resists deformation under heavy loads
• Rated to support G.V.W up to 40,000 lbs per block

Can I use these blocks with different jack types and trailer styles?

Yes — the block’s shape and size accept a variety of feet, including round 9" fifth-wheel hydraulic jack feet, tongue jacks, scissor stabilizers, square posts and standard jack pads. The stackable design also helps you match the height needed for leveling on uneven surfaces.

• Compatible with tongue jacks, 5th-wheel jacks, scissor stabilizers
• Works with round and square foot configurations
• Stackable layers let you fine-tune height quickly
• One pack provides a single, heavy-duty support block

What are the materials and durability features I should expect?

ROBLOСK uses a reinforced polymer blended with anti-UV additives to resist sunlight, dirt and oils so the blocks keep integrity over many seasons. The polymer formulation maintains stiffness under load while avoiding cracking that can occur with cheaper plastics.

• High-performance polymer construction for long service life
• Anti-UV additives help prevent sun damage and brittleness
• Resistant to grime, oil and outdoor contaminants
• Designed for repeated stacking and heavy loads without deformation

How portable and easy to store are these jack blocks?

Each block includes a side hole plus a rope handle to make carrying easier, and the set ships with a storage bag to keep blocks together and compact in your RV bay. The single-block pack is lightweight enough for one person to handle yet strong enough to support heavy trailers.

• Built-in carry hole and rope for simple transport
• Included storage bag saves space and keeps gear tidy
• Stackable design reduces storage footprint when not in use
• Single-block format suits owners who need occasional stabilization support

Who is this for: The ROBLOCK 6" trailer jack block is ideal for RV owners, travel trailer and fifth-wheel drivers, weekend campers and anyone who needs a dependable, portable base under a jack or stabilizer. If you want straightforward height adjustment, strong load capacity, UV-resistant materials and a carry-ready bag, this block provides a simple, durable solution to reduce sway and protect jack feet during camping, storage or roadside stops.