Fizik aliante vsx kium saddlethe versus x saddle takes the level of comfort one step further for the vs range the central channel design has a more ergonomic shape with additional padding which relieves pressure even more the versus x has a maximum channel width of 30mm and depth up to 20mm for optimum pressure relief aliante vs x is for the bull rigid spine if you have a relatively low degree of spinal flexibility more than 90 degrees between your straight legs and back when bending over