It takes a wee bit of practice balancing these (I use a small stamping block on top of a bigger stamping block) but they are VERY popular for custom orders!
This is a terrific item for non-wearers of jewelry. As Kathy points out, they can be awkward to stamp because they’re not totally flat. As always, don’t buy just one! You’ll be keeping the first try ;-)
As others said, this one takes practice. I made the mistake of only buying one and wasn’t 100% happy with it, but again, this is more user error due to never working with these before. Always buy a practice piece (or two!)