Chinese wax injectors

Wondering if anyone on here has any experience with the Chinese wax injectors all over Ebay…especially the ones that are advertised as being “vacuum & pressure”? Do they really have vacuum capability like the Japanese Yasuis or are
they strictly pressure machines that are mis-advertised? Quality and reliability???
We’re looking for vacuum capability but don’t need any expensive “boat anchors”, “door stops”, or balloon ballast.