  Results are presented of the spin-parity analysis on a sample of centrally
produced mesons in the reaction (p p -> p_{slow} K_s K_s p_{fast}) with 800 GeV
protons on liquid hydrogen. The spin-parity analysis in the mass region between
threshold and 1.58 GeV/c^2 shows that the (K_s K_s) system is produced mainly
in S-wave. The f_0(1500) is clearly observed in this region. Above 1.58 GeV/c^2
two solutions are possible, one with mainly S-wave and another with mainly
D-wave. This ambiguity prevents a unique determination of the spin of the
f_J(1710) meson.
