A brass olive insert for AN3 PTFE hose ends. In a PTFE hose assembly the olive slides between the PTFE inner tube and the stainless braid, and is squeezed as the fitting is assembled to form the seal, so it is the single most important part of the joint. Brass is used because it deforms readily against the PTFE without cutting it. This is a strictly single-use item: once a PTFE hose end has been assembled and stripped, the olive has already taken its final shape and must be replaced. Anyone reusing AN3 hose ends on brake or clutch lines should keep a supply on hand, since a reused olive is a leak looking for somewhere to happen.