I showed a rattle before - this is a variant (for new grandnieces). The dumbell ends and rings are 50mm diameter (in line with new US standards, which also dictate no handle) and the colours are readily-available food dyes, and thus I believe safe to be sucked. This last is an idea from a US discussion group when I could not get a straight answer on safety from UK wood stain supplier. The wax finish is wax oil of a type specifically approved for young kids toys, and the wood is sycamore. I used a 10mm diameter special ring separating tool in this case but clearly one could manage without. Good to remember to sand the rings before quite separating them - much easier (though sandpaper stuck to the central rod with double-sided sticky may still be needed to finish the ring interiors).