I created the tree rings with AI make
it was very easy
the immediate opening in XCS is also practical
an exact description is important 
at first I only had tree rings simple design
well what can I say that's what I got
3 simple rings in different sizes :D

in XCS I have added a tree from the XCS selection
put it on top and created a copy
I subtracted a copy from the background
the laser does not need to laser anything that is then covered again
added a ring on top
and then everything an outline with 0,1mm 
made this even simpler with edit node

everything at hand
a string and a bell
stick the tree on the pane and put the string through the clamp and the hole in the pane