Motion Pro is dedicated to producing the most versatile, unique and durable products for professional and home use. Motion Pro tools are designed to be simple to use, yet durable enough to withstand the harshest conditions. One of their goals is to offer tools of convenience. Do it right the first time with Motion Pro Tools. For use on Harley-Davidson® Big Twin (excluding Twin Cam) with slotted screw tappet oil filter screen cover. Designed for use with 7/16" combination wrench to allow for maximum rotation without touching engine cases. O-ring design retains the tool in wrench or socket. Flange design allows downward force to be applied to tool. Can be used without removing exhaust pipes on most bikes. Note: Tappets should be serviced every oil change.