Tail vein injection made easier! The Tailveiner is the first easy-to-use mouse and rat restrainer specifically designed for tail vein injections. Slotted tube permits the rat or mouse to be quickly pulled in by the tail. The animal is then restrained by a plug which slides easily to accommodate any size rat or mouse, but locks automatically when handle is released. After dosing, the handle is lifted and the plug is easily removed. The Tailveiner is the fastest restrainer yet for intravenous injections in small animals. Now includes a free stopper/plug option. Advantages of the red tube vs. the opaque tube Laboratory rodents are largely color blind, so a red tube simply looks like a comforting shelter. The Red Tube is transparent, allowing the investigator to observe the animal inside for normal body position and breathing. Improved comfort for rats and mice during acute experimental procedures without sacrificing safety or welfare.