# Difference
```js
difference(){
//outer ring
cylinder(h=9, r= 20 , center=true);
//inner This needs to be taller and have a smaller radius
cylinder(h=10, 18, center=true);
}
```
# Transition
```js
// Translate [X,Y,Z]
translate([3,0,0])
cylinder(d=10, h=10, center= true);
```