A 4 mm grommet listing must identify whether the dimension refers to the mounting hole, internal passage or another feature. Compare the complete drawing before selecting a part.
A molded panel grommet is different from an O-ring, sheet rubber or continuous edge trim. For a grooved grommet, check panel thickness, groove dimensions, flange clearance and cable passage.
Choose the compound and hardness for the actual environment. Small size does not establish a water seal, vibration performance or resistance to every chemical. Follow the installation instructions and inspect the part for cutting, distortion or incomplete seating.
