The K0SK±π∓final state in two-photon collisions is studied with the L3 detectorat LEP at e+e−centre-of-mass energies from 183 to 209 GeV with an integrated luminosityof 664.6 pb−1. Theη(1475) and f 1(1420) mesons are observed and their contribution isseparated by measuring the formation rates as a function of the photon virtualityQ2. Theη(1475) is found to be dominant forQ2≤0.01 GeV2and its two-photon width is measuredto be 0.23±0.05 (stat.)±0 .05 (sys.) keV. At higherQ2, the f 1(1420) is formed and decaysto K∗(892)K. Theγγ coupling and form factor parameters of this state are measuredto be Γγγ = 3.2±0.6 (stat.)±0.7 (sys.) keV and Λ1= 926±72 (stat.)±32 (sys.) MeV,respectively.