  We report a detailed investigation into the metamagnetism of Sr3Ru2O7 at low
temperatures for the magnetic field parallel to the ruthenium oxygen planes.
The metamagnetism is studied as a function of temperature, magnetic field and
sample quality using magnetisation, magnetotransport and specific heat as
probes. From hysteretic behaviour in the magnetisation, we confirm earlier work
and observe a finite temperature critical point at (5 T, >0.25 K). In our
highest quality samples two-step metamagnetic transitions are additionally
observed at 5.8 T and at 6.3 T, which coincide with a range of broad maximum in
the magnetoresistance. At low temperatures, these two metamagnetic features
each further split in two. Such behaviour of the multiple transitions are
qualitatively different from the first order transition at 5.1 T.
