Bicycle rollers for training. Redwood frame, 4" x 14.5" steel rollers. Complete and in fine working condition. The large steel rollers give these a bit of a flywheel effect that creates a smoothness you don't get with aluminum or plastic rollers and the 4" diameter drums are easier on tires than smaller rollers. They are relatively quiet as far as rollers go, and the tall sides with non-slip pads make it easier to mount the bike if you don't use a low step. They roll smoothly, but I have never felt the need for additional resistance, merely shifting to a higher gear when I wanted to work harder.
Rollers are great for off-season training. They are more interesting to ride than a trainer and they help you work on strength, balance and a smoother pedaling style. They are no harder on tires than riding on a smooth road. I've introduced many people to riding rollers over the years and almost all of them were comfortable with them after just a few minutes.