Not applicable.

The friction-grip stem of these casters is pretty stiff, but that's probably a good thing. You don't want the wheels falling out when you lift your amplifier. I had to use a screwdriver to pry the caster out of the cabinet receptacle (before installing them). So, just to be sure, I hit each stem with a short spray of silicone lubricant before final installation.

Ease of Installation: I installed mine into a brand-new Fender '65 Deluxe Reverb Reissue. On that amp, the reverb tank is loosely suspended inside at the bottom floor of the amp. I first removed the tank (just two screws), to be certain that my drill bit wouldn't hit it. (After installation of the casters, it was necessary to reinstall the reverb tank with longer screws so the tank would suspend nicely above the caster shafts that poke through the amp's floor. I used two inch-and-a-half self-tapping wood screws and it works perfectly.) The best position for the casters would be as far out to the corners of the amp as possible, to maximize stability when rolling over thick carpeting or other uneven surfaces. But the amp has "gliders" at those positions. I considered removing the amps gliders and then decided against it, because if I were to use the amp without the casters, (and gliders) then the amp would be resting upon the casters' cabinet receptacles, which might be damaged. So that left me with fewer options for positioning. I ended-up installing them as close to the amp gliders as possible, and it works great. This amp does have a tendency to tip forward or backward when negotiating my thick living room carpet, but it rolls smooth as silk over tile and cement walks, etc. Amps that are deeper than the Deluxe Reverb will be more stable. This "problem" was not a deal killer for me. After carefully marking the position for your center holes, drill the 5/8" center holes. Then put the receptacle's shaft into the hole. Now, you can mark the positions for the 4 smaller holes that accept the attachment screws. I had to buy a 5/8" woodworking drill bit. It took awhile to bore through the Fender's hard plywood, but that's not a complaint. I love Fender's robust construction. All-in-all, I would rate the Ease of Installation as 7 out of 10 (10 being the easiest).

These are well-made casters. The tolerances seem to be quite good. I'm assuming that the tightness of the wheels in the fittings is a good thing. Really, these casters should last forever unless mercilessly abused.

No need to call the manufacturer.

price is good

Casters aren't sexy, but these are good-looking in a utilitarian way. Putting casters on an amp doesn't sex it up, but it doesn't look bad, either. It just saves lugging the amp around by the handle.

I doubt that these casters will ever wear out. I looked for "genuine" Fender replacement parts, and found them to be more expensive. Took a chance on these instead, and I'm happy I did.

Smooth operation, quickly removable. Wheels weren't quite as big as I expected, but very adequate.

Rugged. Time will tell about rust or corrosion.

Cheap for what you get.

It would've been okay to install if my cab had a hole in it a half of an inch thick and an inch long because i had to drill my cab to get the rod in thats sticking out of the wheel. It took a really long time and was very stressful. I reccomend buying a more supportive flat wheel instead of the rodded wheel.