The Wodent Wheel Senior wheel by Transoniq is one of the safest wheels on the market. The running area is fully enclosed so there is no way for your pet to ever get caught between the stand and the axle. With an 11-inch diameter, it is perfect for small pets such as hamsters, sugar gliders, mice, small rats (but not meant for big chewers such as gerbils). It comes with a free tail shield fully covering the axle which is needed for animals that grip with their tails such as sugar gliders. It also comes bundled with Ware Critter Pops, crunchy puffed rice treats that will keep your pet engaged. Put them on a Ware Treat-K-Bob or just give them individually.