This adaptor's design prioritizes the secure and humane holding of the rat, employing a three-point fixation system (incisors grip, nose clip, and ear bars) to minimize stress and movement during procedures. It boasts a substantial range of adjustability, with a vertical movement allowance of up to 30 mm and a horizontal extension of up to 50 mm, accommodating rats of different sizes with ease. The scaling resolution of 100 μm ensures that adjustments can be made with precision, allowing researchers to replicate positioning accurately across different sessions and subjects. Although ear bars are not included, the adaptor is designed to be compatible with them, offering flexibility in securing the rat's head based on the specific requirements of the procedure.