In LPE garnet films strong spin precessions can be excited locally by microwaves near the ferrimagnetic resonance frequency. When the precession angle ϑ exceeds a critical value the spins tip over and create a bubble within which the spins keep on precessing due to the microwave excitation. With further increasing ϑ a second critical value is reached where the spins again tip over and create a bubble within the the first one, i.e. a ring domain. Continuing in this way systems of many concentric rings can be generated which are stable even in the case of vanishing microwave power. However, single ring domains in films of low coercivity can only be stabilized by microwaves. To a first approximation the stabilizing forces on these domains are due to the precession induced change of the dc magnetization inside the ring. If the microwave stabilizing a single ring domain are amplitude modulated a corresponding radial motion of the ring is induced. From this motion one can derive the eigenfrequency and velocity of the ring.