Foam. 10″ wide. The Bare Bones solo seats are designed to look as thin and narrow as possible, even lower than the Silhouette solo. This gives an unbelievably sleek, low profile. Will complement the lines of every bike from stock factory to radical custom. Note: 00-17 Softail seats come in three versions. 00-07 with tires up to 150mm, with frame mounted seats. The 08-17 models, with tires up to 150mm and 06-17 200mm Wide Tire models with fender mounted seats. These are not interchangeable.