4PCS 6in RV Trailer Jack Block Set - Stable, Stackable Support

In this review of the 4PCS 6in RV Trailer Jack Block set the bottom line is simple: this kit is for RV and trailer owners who need a tough, stackable support solution that stops sway and movement when parked. The reviewer found the blocks work with a wide range of jack feet and stabilizers, delivering predictable leveling and peace of mind on uneven ground. Built from a high-performance polymer with anti-UV additives, these blocks feel solid under load and are easy to carry and store in the included bag.

Key Features

• All-in-One Compatibility: Fits nearly any tongue jack foot, wheel jack, 9 round 5th wheel hydraulic feet, and scissor stabilizers so you do not need multiple adapters.
• Heavy Duty Construction: Made from a high-performance polymer with anti-UV additives to resist grime, oil and sun exposure for long-term outdoor use.
• High Load Capacity: Each block is rated to support a G.V.W of about 40000 lbs per block, providing confidence under heavy loads.
• Stackable Adjustable Height: The stackable design lets you change height in small increments to achieve precise leveling on uneven sites.
• Convenient Storage and Transport: A side hole with rope and a compact storage bag make carrying and storing the blocks straightforward and space saving.

Who It's For

This set is best for owners of travel trailers, campers, and fifth wheels who need a reliable, universal support that reduces sway and movement when parked. It works well for those who move frequently between campsites and want a lightweight, durable solution that stacks for fine height adjustments.

Those who should look elsewhere include users who require metal jack adapters for permanent mounting or very specialized feet shapes not compatible with polymer blocks, or operators who need built-in mechanical leveling systems rather than manual stacking.

Pros & Cons

Pros

• Excellent stability under load, reported by customers as resisting sway and movement effectively.
• Solid build quality with UV-resistant polymer that stands up to dirt and oil.
• Versatile fit for round and square jack feet, scissor stabilizers, and many 5th wheel hydraulic feet.
• Easy to carry and store with rope hole and included bag.

Cons

• Polymer construction may not suit those who prefer metal blocks for permanent, high-wear installations.
• Height increments depend on stacking whole blocks, so very fine single-quarter-inch changes are not possible without additional shims.

Specifications

Set Includes	4 blocks and storage bag
Height	About 6in per block
Length	11.5in
Width	11.5in
Material	High-performance polymer with anti-UV additives
Load Capacity	G.V.W 40000 lbs per block (manufacturer stated)
Carry	Side hole with rope and storage bag included

Our Verdict

The 4PCS 6in RV Trailer Jack Block set is a practical, value-oriented choice for trailer and RV owners who want a universal, stackable support that reduces sway and levels reliably. It combines durable polymer construction, high load rating and easy transport in a compact package, making it a sensible buy for campsite leveling and short-term stabilization needs.

Frequently Asked Questions

Will these blocks fit my scissor stabilizer?
Yes; the blocks are designed to accept scissor stabilizer feet as well as round and square jack feet.

How many blocks do I need to reach a greater height?
Blocks are stackable, so add blocks incrementally to reach the desired height; each block is about 6in tall.

Is the material weather resistant?
Yes; the polymer includes anti-UV additives to resist sun, dirt and oil for extended outdoor use.