Summary: Let \(\mathcal{B}\) be an infinite subset of \(\{1,2,\dots\}\). We characterize arithmetic and dynamical properties of the \(\mathcal{B}\)-free set \(\mathcal{F}_{\mathcal{B}}\) through group theoretical, topological and measure theoretic properties of a set \(W\) (called the window) associated with \(\mathcal{B}\). This point of view stems from the interpretation of the set \(\mathcal{F}_{\mathcal{B}}\) as a weak model set. Our main results are: \(\mathcal{B}\) is taut if and only if the window is Haar regular; the dynamical system associated to \(\mathcal{F}_{\mathcal{B}}\) is a Toeplitz system if and only if the window is topologically regular; the dynamical system associated to \(\mathcal{F}_{\mathcal{B}}\) is proximal if and only if the window has empty interior; and the dynamical system associated to \(\mathcal{F}_{\mathcal{B}}\) has the “naïvely expected” maximal equicontinuous factor if and only if the interior of the window is aperiodic.