The X5 uses earpieces that are just a little larger than the originals, which are being renamed X10. The diameter of the 'bud' may only be 2mm greater, but apparently this makes it both easier and slightly less expensive to manufacture.
The company says this will enable it to "pass the savings on to the end user": UK pricing for the X5 is yet to be announced, but in the States the X5s will sell for about 30% less than the X10s.
The new headphones come with five different pairs of ear gels, and are supplied complete with a carrying pouch, an in-flight adaptor and a cleaning tool for the ear gels.