The Tacx Antares Rollers Trainer allows you to cycle at home in comfort to really see results. As well as assisting with stability and confidence, they will refine your coordination and technique in the process. And while it takes a little practice to use, it's almost impossible to ride off the machine. The Antares is collapsible and measures only 80 cm when collapsed, making it easy to carry. A support is available separately for riders who would rather ride without a front wheel to begin with. Antares With the Antares roller, you can cycle freely to refine your coordination and technique. This roller can be retracted to 80 cm. Conical rollers The Tacx rollers have conical rollers which ensure that your bike always remains in the middle of the roller while youre riding. This makes riding on the rollers easier and safer. Retractable The Tacx rollers are retractable to 80cm.  Features              Type of trainer- RollerRoller diameter - 100-110mm (3.93-4.33in)Suitable bikes -