有人知道end over end rotator是什么仪器吗

One milliliter of methanol was added to the dried lysate and sonicated for 1 min, on/off cycles of 2 s on, 3 s off, at 100% power on a Qsonica ultrasonic processor.The samples were then placed on an end over end rotator and metabolites were extracted overnight.

文献里是这样说的，超声完了放在这个end over end rotator上过夜提取，有人知道这个是个啥东西吗