  Small momentum transfer elastic proton-proton cross-section at high energies
is calculated assuming the nucleon composed of two constituents - a quark and a
diquark. A comparison to data (described very well up to -t = 2 GeV^2/c) allows
to determine some properties of the constituents. While quark turns out fairly
small, the diquark appears to be rather large, comparable to the size of the
proton.
