Windshield Wiper arm nut cover Volvo 240 sedans and wagon. This is for the larger mounting base BOSCH wiper arm. To install this part in place without disassembly of the arm, a small section shown in red on one of the pictures have to be cut out.This will allow the cap to slide over the swivel point pin of the arm mount. The purpose of this cover is to keep moisture from getting into the wiper arm shaft housing . These are injection molded on our own tooling,