The PLAS-LABS' Rabbit Restrainers are clearly the best. They provide total observation of your valuable research animal. All Rabbit equipment was originally developed in the early 1970's in research labs under actual research conditions. We were the first to use clear acrylic materials to protect and safeguard your animals. Eliminates or minimizes back injuries. Standard Features of the Rabbit Restrainers: Highly polished edges prevent chaffing, especially at the neck. Non-slip surface provides better footing and helps to calm animal. This is much safer and easier on the animal's foot pads. Clear acrylic aids in retaining body warmth. Hypothermia is eliminated. Unique curved back butt plate minimizes the risk of back injury. The plate is anatomically correct. Vertical head bars are adjustable and easily removable if not needed. Rear access hole for pyrogen testing (N/A on 501-TC). Stainless steel pin offers several fine adjustment points for neck plate. Unit can be sanitized in a cage washer up to 180 degrees F degrees (82 degrees C) or sterilized chemically. Non-slip base pads ensure unit stability.