Rubber o-rings in size 12x1mm suggested to use for XRAY XB4 shock absorbers in the upper cap to prevent the shocks from leaking.

  XRAY XB4
  XRAY XB4 2014 Specs
  XRAY XB4 2WD
  XRAY XB4 2016 Specs
  XRAY XB2 - Carpet Edition
  XRAY XB2 - Dirt Edition
  XRAY XB2 2017 - Carpet Edition
  XRAY XT2
  XRAY XB4 2017 Specs
  XRAY XB2 2017 - Dirt Edition
  XRAY XB2 2018 - Carpet Edition
  XRAY XB4 2018 Specs