The old stabilizers were rusted, but still worked.
The new ones have hex heads to connect the crank, can lift 4500 pounds each, more than the weight of the trailer, and the weight is distributed across four of them. Despite the warning not to use the stabilizer as a tire jack (do they mean without mounting it?), they can easily lift the trailer off of the wheels.
I use a Ryobi battery-powered electric drill that has a 12 volt DC charger. I can use it in the tow vehicle or on solar power.
I also have a 120 volt AC charger in my shop to get the batteries ready before a trip.
I deliberately installed my stabilizers “crooked” so that they won’t be parallel to each other. When they are parallel, the trailer sways more in the lengthwise direction when the stabilizers are down. I was able to reuse some of the original holes in the trailer frame, and had to drill others.
Raising the stabilizer holds it in place while I install the self-tapping bolts. It comes with at least 4 self-tapping bolts per stabilizer.
These new stabilizers work well, don’t sway, are over-rated for the weight they carry, and are fast and easy to raise and lower. They were convenient while I later replaced the old brakes with self-adjusting ones, and replaced the hub, drum, bearings, and seals.