The ISIS Headbox is used in ENT and neurosurgery. Every ISIS Headbox with integrated preamplifier is made of eight amplifier channels. These channels are made for multfunctional use. Moreover, an AEP stimulation output can be added. Digitization of recorded signals happens in the Headbox and done by a processor. It is then transmitted to the PC without any interference. This results in acquiring optimum signal even during challenging conditions in the operating theater. ISIS Headboxes stimulate and record evoked potentials on a medical-approved computer. ISIS Headbox (article number 504 260) comes with 8 single-ended channels used for SEP, EEG, and VEP while ISIS Headboxes (first article number 504265, second article number 504280) also have 8 single-ended channels each and are used for EEG, VEP, SEP, and AEP monitoring. ISIS Headboxes with first article number 504270 and second article number 504275 have 8 differential channels each and used for MEP and EMG monitoring.