Well we all know the Xtool brand Flasks are curved, in fact it has a diameter of 13.75" or 395 mm so here is how you are able to engrave right to the edges. Set your focus with kick stand in middle of highest level of flask, then add 2mm positive focus which mean raise laser module by 2mm higher than the regular kick stand focus. This will then engrave to the outer edges of the curved flask no problem.