The JB200 is the only vaporizer on the marked with an build in sliding stop for the acid tray.
This prevents the hot, acid filled tray, from sliding down the heat element into the hive during evaporation. This also prevent the tray from tipping sideways and spilling the acid.
The JB 200 high-speed oxalic acid vaporizer comes with a "free standing acid tray" and a heat protector to prevent scorching. The acid tray has no contact with the metal screen or wooden bottom in your hive and evaporation of the acid starts in approximately 15 seconds.