What exactly is the difference in the Hikvision type numbers?
Differences in model number:
Model numbersprovided with the I are IP67 water and dust resistant and IK10 impact resistant.
Model numbersfitted with the ISU On top of that, they have a built-in microphone.
Model numbersfitted with the ISU/SL On top of that, they also feature a built-in flash light and speaker that can be used to deter an intruder by sounding a siren or playing a voice message from the camera. Or that the strobe strobe light flashes brightly a few times.