I have a really cool, lightly-used Minoura Mag trainer that works perfectly. To change the tension, it has a cable to bind to the handlebars. It looks good, and it's pretty.
With 7 different levels of resistance that can be operated from the handlebar mounted shifter, the Minoura Mag Turbo Trainer gives a quiet and smooth feel. A 35 percent wider range of resistance than regular mag trainers is provided by the single Neodymium magnet. The LR341 Mag trainer works with most adult bikes and suits hub widths ranging from 120 to 148 mm and wheels with a maximum tyre width of 45 c from 24 to 700c.