Bought a bunch of second hand electric pipet controllers. Interesting to compare the different brands. I like the INTEGRA PIPETBOY acu, fancy color, transparent – no black box, easy to open and service with screws. Uses standard 9V accu batteries. Eppendorf and Brand, both no screws and non standard batteries. They all work perfectly fine. Just had to find the right adapter – INTEGRA works on 12VDC standard barrel jack, Brand 5VDC and Eppendorf 9VDC.