ROBLOCK 6"H 4-Pack Trailer Jack Blocks for RVs — Stackable UV-Resistant Stabilizer Blocks

ROBLOCK 6"H trailer jack blocks are durable, stackable polymer risers that stabilize and level RVs, travel trailers and fifth-wheel jacks while eliminating sway in parked campers.

These four heavy-duty jack blocks from ROBLOCK are engineered to take the weight and movement from tongue jacks, scissor stabilizers, round or square jack feet and fifth-wheel hydraulic pads. Made of a reinforced, UV-resistant polymer, each block supports substantial loads while resisting grit, oil and weathering. The stackable design lets you fine-tune height, and the included carry bag and side-hand hole make transporting and storing the set straightforward.

How do these blocks make my trailer more stable when parked?

By increasing the surface area under your jack foot and removing vertical play, the ROBLOCK jack blocks reduce rocking and side-to-side sway from movement inside the camper or from wind. Multiple blocks can be stacked to match the exact height your setup requires.

• Large top pad spreads load to prevent sinking on soft ground.
• Solid polymer construction limits compression under heavy loads.
• Stackable design allows incremental height adjustments.
• Fits round, square, scissor or hydraulic jack feet for broad compatibility.

Will these blocks handle the weight of big trailers or fifth-wheels?

Each ROBLOCK unit is rated for very high gross loads thanks to its reinforced polymer blend and anti-UV additives. When used as intended — stacked or singly under jack feet — they provide a dependable platform for heavy travel trailers and fifth-wheel landing gear without cracking or deforming.

• High load capacity per block for demanding rigs.
• Engineered to resist oil, dirt and long-term sun exposure.
• Stable geometry reduces tipping risk under lateral forces.
• Smooth underside and wide base for reliable ground contact.

How do I choose the right number of blocks and arrange them?

Start by placing one block under the jack foot and check clearance and level. Add additional blocks until you achieve the required height and stability. Blocks nest securely when stacked so alignment stays consistent under load.

• Use one block for small adjustments or flatter surfaces.
• Stack two or more for larger lifts or uneven ground.
• Align the top pad with the jack foot center for even weight distribution.
• Carry and store blocks in the included bag to protect them and save space.

How portable and weatherproof are these jack blocks?

ROBLOck blocks are lightweight enough to carry but rugged enough to endure outdoor storage and repeated use. A molded side hole and rope plus a zippered storage bag make transport simple, while UV-stabilized polymer resists fading and breakdown from sun and grime.

• Molded side hole and rope for quick transport or hanging storage.
• Included carry bag keeps blocks organized and compact in your rig.
• Anti-UV additives slow weathering and extend service life.
• Easy to rinse clean after muddy or oily conditions.

Who is this for: These ROBLOCK jack blocks are designed for RV owners, travel-trailer and fifth-wheel drivers, campgrounds and maintenance crews who need a reliable, portable way to level and stabilize trailers. They suit anyone who wants corrosion-free, stackable supports that fit most tongue jacks, stabilizers and landing gear without adding heavy metal plates or complicated hardware. If you need quick setup, adaptable height control and long-lasting outdoor durability, this 4-piece kit with carry bag is a practical addition to your RV toolkit.