The new SR-5R-HT Stereotaxic Instruments in our successful SR series are designed specifically for rats, and feature various special functions to fix the head more firmly. Smooth manipulation of clamping actions with one hand is made possible by the auxiliary ear bar, and the operator can check that the external auditory canal is fixed correctly by feeling with the fingertips. The mouth and nose fixing clamp is designed thin and small, to match the dimensions of a small rat’s mouth, allowing easy confirmation of teeth fixation. In addition, the instrument allows easy back/forward and up/down position adjustment. An AP frame bar is provided, to which many different types of accessories can be attached along with the attached micromanipulator: SMM Series (SMM-100 / SMM-200) or SM-15R/L. The SR-5R-HT has one AP frame bar, while the SR-6R-HT has two.