I took these out of the box and assembled but never actually put a bike on them.  They look like very nice quality, slightly textured aluminum rollers with very nicely spinning bearings.  The rollers measure 3 inches in diameter.  The frame is steel and they fold up for easy storage.  These are a great lesser expensive option to the kreitler rollers, without getting cheap plastic rollers.  They should fit any standard bike.  I paid a little over $300 about a year ago. 

Thanks for looking and feel free to ask any questions!