Water key spring for Getzen, Edwards, Roth (Roth, not Rath) and Reynolds trombones. This is a medium-weight 7-winding spring with a 3/8-inch (9.5mm) nose (measured from base of spring coil to tip of nose). The spring is about 9/16 to 5/8 inch (14 to 16mm) wide. Tails should be clipped after installation.