Valve Tool, wrench with 5/16 inch Flat and 1/4 inch opened slit end. ARE-Applied Research brand. 5/PK.
Additional Info:
A valve tool is very popular because it is designed to reach onto your HPLC instrument's, Rheodyne™ or a Valco™ injector while tubing is still attached to the injector or for use on other valves with 1/4 inch connecting nuts.
Easy to tighten or loosen the 1/4 inch connecting nuts without twisting the tubing during wrenching. The opposite end of this valve tool is a 5/16 inch flat wrench.