Got it. Works well. Got the exact same reading as with the hyrdovolt. So it looks to be accurate. BUT, I will not be using it on a regular basis. You have to hold the refractometer exactly surface level, otherwise you get acid on your hands and the meter (were gloves, duh). Still. Takes a really long time to use. Take pipette, get acid from the cell, put it in the meter, hold it steady and level, make sure no drops fall off, close lid, read it. Then clean it. Repeat 23x. It could take an hour to take readings from all 24 cells of a 48v forklift battery. Hydovolt is super quick and no acid spills. Good to have an option though. Might use it to check 6 cells on 12v battey, any more is too much work. Hydrovolt wins hands down. Plus it has the temperature calibration function built in. I will never go back to bulb style. Anyway, my 2 cents worth.