  Measurements of hadronic final state interactions in W-pair events at LEP are
presented. In particular, different scenarios of colour reconnection are
studied. The data agree with moderate colour reconnection effects. Extreme
scenarios are ruled out, limiting the systematic uncertainty on the LEP W mass
determination due to this effect. An updated measurement of the mass of the W
boson at LEP yields 80.412 +/- 0.042 GeV.
