XFit Technology

XFit technology considers the body shape and body style of individuals for a custom and more comfortable fit. Everybody is shaped differently - your diaper should be made for YOU. By providing a custom fit, XFit eliminates leakage, long lasting wear, and quality comfort. UnderX is the only brand on the market that takes into account your specific body shape. It accommodates people who have thinner legs and broader waists or those with larger legs and thinner waists.

If you are an ectomorph - you may be quite thin all around. Your limbs may be thinner because of your skeletal make up. These body types are lean muscle retainers and have difficulty gaining weight. Mesomorphs are typically a little thicker in build with a broader hip and leg ratio. They also lose and gain weight easily in comparison to the other body types. Endomorphs have the thickest build of the three - with a thick bone structure and a higher capacity for retaining body fat and may gain weight easily. If none of these sound like you, don’t worry because Underx still has you covered.

The sizing system of XFit has overlapping sizes. Underx sizes go as follows:

  • A Medium is 31”-47”
  • A Large is a 43”-59”
  • An X-Large is 47”-67”

If your waist is large but your legs are skinny, you may want to chose a size down so that the leg cuffs are snug and the waist fit is still comfortable. If your legs are thicker and your waist is thinner, consider sizing up in order to get a snug fit on your legs while still considering the fit to your waist.