1. The clearance between the outer diameter D of the rubber ring and the inner diameter of the chamber is not more than 2mm.
2. The gap between the inner diameter d of the rubber ring and the outer diameter of the cable shall not be greater than 1mm.
3. The rubber ring width A shall not be less than 0.7 times the outer diameter of the cable, but not less than 10mm.
4. The rubber ring thickness B shall not be less than 0.3 times the outer diameter of the cable, but not less than 4mm.
