5-Pack OX BLOX Heavy Duty Trailer Jack Block - Made in USA RV Leveling Blocks - Supports Up to 10,000 lbs - RV Jack Blocks for Any Tongue Jack, Post, Foot, or Stabilizer (Round or Square)

Delivered within a day! Wow! Haven’t had a chance to use it but if it performs as well as it looks and feels, this is a winner all around.

This product is heavy duty and performs as expected. Please note that the block features various color specs and is not entirely black. If you're looking for a solid black appearance, I recommend checking the specific product details or images before purchasing to ensure it meets your expectations.

Looks to be durable, works well

I have a total of five of these. One for over a year and four I purchased in June 2024. I have an inclined driveway and I use two under each of the front stabilizers and one under the front trailer jack. They have held up well to heat, sun and cold. When stacked they have a nice secure interlock. They are a bit heavy, but are solid and well made. I would definitely purchase these again.

Before getting we were carrying multiple pieces of wood. Those are not necessary now. It sturdy and strong.

These blocks are fantastic, with one caveat. I have an 1100 lb slide in pickup camper which I store on a settled, stable gravel driveway. I have stored the camper jacks directlly on the gravel many times before, using just the camper jacks with their 8-inch metal bases, and pieces of wood decking boards under the bases on the gravel. The first time I placed the same rig on these new blocks, the whole setup was also very stable. I even used a level to make sure the rig and blocks were level. After about 6 hours on a very sunny day, with temperatures about 95 degrees F, I noticed the front camper jack metal base plates had moved slightly forward on the forward BLOX - about 1/2 to 3/4 of an inch. The rear jacks were stable, and not in the same direct sunlight. So what? My sense is the top surfaces of the front blocks got a little "greasy" in the sun. And an almost invisible, slight forward weight shift onto the front jacks caused this slow sliding motion. Again. This was never a problem, and the blocks work great. But I would pay close attention to using these on any gravel placement.

These are very thick and sturdy. Stack well. If you’re using them on a fifth wheel with a round platform on the end of the leveler, you need to take that off and just use the pole itself. I wish it would accommodate the round platform at the end of the leveler instead of having to take that off

Ended up buying three of them for different things, but they are so much better than a cinderblock. They don’t sink into the yard as bad and are so much easier to handle.