Instructions are weak and with both units I had to prime the pump. Nothing in the documentation shows that. I thought both units were dead. Finally got them going and operation is as described and is very accurate. I used water to set the fill times for each bottle size I have and that transferred to oil very well. The pump is strong and has no problem keeping up. I set the fill rate to 70. I am ordering 14 more of these as switching between different liquids is a bit of a pain. You cannot get the draw and fill tubes clean without a flush and a re-prime. This is expected tho with auto fillers. So instead of wasting aroma oil on a change over, dedicated units are the way to go. Gravity or manual machines have the same requirements to clean and re-prime before changing liquids to prevent contamination. I did the math and with this machine change over you will burn approx 50 cc's of oil. In my world thats money down the drain. Dedicated machines will pay for themselves in no time. Great machine over all.