This magnetic version fo Newton's cradle is no longer in production, but somtimes found on ebay:
From eBay: Search NOW: Magnetic Newon's Cradle
Magnetic Newton's Cradle: the famous collision demonstration reimagined with opposing magnets as the pendulum weights- shown here in two modes of operation. Initially the collision pattern looks similar to the traditional colliding spheres version but quickly goes chaotic- the magnetic field of each weight interacts with all the other magnets simultaneously making the system nonlinear. A 1990s desk toy by Fascinations- sadly no longer in production.