This circular seal has a number of design features worth noting. In use, the seal is sandwiched between the larger blue plastic housing and the blue plastic "lead ins" shown at the front of the picture. Around the outside, the seal has a series of rubber fins that are designed to allow a coupler to easily slide over them, but then the fins begin to roll up if the coupler is attempted to be removed—a very effective one-way seal.
Inside, either three or four holes are designed to accept varying sized plastic conduit. Each hole is sealed with one raised bead that insures an air-tight seal no matter how out-of-round the plastic conduit. By integrating both the outer seal and the inner seal in one rubber part, the customer has reduced its Bill of Material and also reduced the complexity of assembly.
The rubber parts pictured are not in stock or for sale. These are examples of custom-manufactured products that illustrate Custom Rubber Corp.'s capabilities.