For O-rings there are all sorts of auxiliary tools that you can use. To help with installation, for example, there is the O-ring picker and the O-ring installation and removal set in a case. This allows you to install or remove an O-ring without damaging it. To measure O-rings, there is the circometer, an O-ring measuring stick, Pi tape and the measure thorn set. Buy one of these auxiliary tools to help determine the size of an O-ring on site. We recommend that only unused O-rings be measured to ensure an accurate measurement. There is also the rubber indicator that can be used to provide an indication of which rubber you should use to make the ring, and this comes with a user manual. As its last accessory, there is the service box. This is indispensable for fitters who need an O-ring on site urgently. With the mitre board, knife, glue and cords of different thicknesses contained in this kit, you can quickly make an O-ring yourself. This service box is available in EPDM, NBR and FKM.