  Inspired by a recently proposed Duality and Conformal invariant modification
of Maxwell theory (ModMax), we construct a one-parameter family of
two-dimensional dynamical system in classical mechanics that share many
features with the ModMax theory. It consists of a couple of
$\sqrt{T\bar{T}}$-deformed oscillators that nevertheless preserves duality $(q
\rightarrow p,p \rightarrow -q)$ and depends on a continuous parameter
$\gamma$, as in the ModMax case. Despite its non-linear features, the system is
integrable. Remarkably can be interpreted as a pair of two coupled oscillators
whose frequencies depend on some basic invariants that correspond to the
duality symmetry and rotational symmetry. Based on the properties of the model,
we can construct a non-linear map dependent on $\gamma$ that maps the
oscillator in 2D to the nonlinear one, but with parameter $2\gamma$. The
dynamics also shows the phenomenon of energy transfer and we calculate a Hannay
angle associated to geometric phases and holonomies.
