These are very nice quality rubber bases.  They are much much nicer than the simple plastic throw bases and will last you a long time.  They are perfect for a trip to the park,  t-ball, baseball etc.  The only reason I did not give them five stars is that the box is very thin and cannot be used as a permanent storage.  The box lasted like two weeks - and then I had to find another suitable way to lug them around (keep in mind - they are solid - so they aren't light).  It would be nice if they would include a nylon carry bag or something with a handle that could be used to permanently store, haul, carry these around.  Otherwise - they are very useful!