This simple and compact SG-3N Head Holder is designed for the purpose of fixing the head, with special consideration paid to the ease of use on a microscope stage. The clamping method is based on three-point fixation (mouth, nose and ears), ensuring that the head is easily and firmly fixed in position. By attaching the mouth/nose clamp and ear bar to a single bar, the instrument allows the head angle to be freely adjusted through 360°. The holder’s overall compact size makes it possible to be used for many different purposes. It can be placed on the iron plate in combination with a thin type magnetic stand (GJ-12). The SG-3N Head Holder is for rats, and the SG-4N Head Holder for mice.