A catheter assembly comprising a first polymer, a second polymer and a first weld region. The first polymer forms a balloon having a first waist. The second polymer forms a catheter shaft. The first waist is positioned about a portion of the catheter shaft thereby forming the first weld region. The first weld region comprises a first weld and a second weld which engage the first waist to the catheter shaft. The first weld has a first longitudinal position and the second weld has a second longitudinal position, where the first longitudinal position is different from the second longitudinal position.