In this study, we examine a bistable shock isolator (BSI) and its shock -transmitting behaviors, particularly when tuned to the zero -frequency singularity (ZFS) condition. Under this condition, a snap -through transition occurs, and the BSI oscillation exhibits critical slowing down. By tuning the BSI to the ZFS condition, harmful shock transmission to the protected platform can be significantly delayed, allowing protective measures to be implemented before the transmission of dangerous forces. Moreover, the magnitude of the transmitted force is reduced considerably. We establish a mathematical model of the BSI and theoretically analyze the ZFS. Using numerical investigations, we demonstrate the benefits of the ZFS in terms of shockisolation performance, including delay and mitigation of force transmission. Parametric and spectral analyses further confirm the benefits of the BSI. We validate the existence of the ZFS and its effects from the perspective of shock isolation by developing a BSI prototype and conducting experiments. Furthermore, the need for future research focusing on the BSI in realworld scenarios is discussed. It is believed that the findings reported herein will pave the way for advances in shock -protection technologies based on nonlinear bistable systems.