I got a pair of them for my SP101, don't care much for them. After some practice they work OK, start them in the cylinder and slide the loader sideways.
BUT they don't retain the cartridges very well. If you were to drop one or try carrying it in your pocket the cartridges will come out of the darn thing.
I thought they'd work good for my bedside gun, just leave 'em in the drawer and if needed slip the ring around the weak hand finger but it's too easy to knock all the rounds loose and loose 'em. They won't fit into standard speedloader pouches either.