Adjustable: Unique spiral grip makes single-size restrainers obsolete. Low stress: Gentle, but secure. Rats can not turn or escape, natural posture maintained . Easy to use: Complete experimental access. Stable and strong: Wide base stands up to daily use, heavy construction. Easy to clean: Opens fully, will not corrode, no blind ends. Plastic and stainless steel construction. Improved technique: Save time and effort when handling laboratory rats. User has both hands free. Relax and avoid accidents, knowing animals are gently but firmly restrained. The Universal Restrainer was designed to have a slot for access to the ventral abdominal area of the rat, suitable for access to urinary bladder, GI catheters and fistulas, etc.. The slot could also be used for intraperitoneal administration of test articles, best for repeated IP injections or an infusion within an experiment.