The Glenair 550-031M1R9K backshell is designed for use with D-Subminiature connectors, specifically accommodating shell sizes 3, 4, and 5. The dimensions for these shell sizes are as follows:
- Shell Size 3:
- A: 2.265 inches (57.5 mm)
- B: 0.624 inches (15.8 mm)
- C: 0.312 inches (7.9 mm)
- D: 1.852 inches (47.0 mm)
- P: 1.594 inches (40.5 mm)
- R: 0.938 inches (23.8 mm)
- Shell Size 4:
- A: 2.900 inches (73.7 mm)
- B: 0.624 inches (15.8 mm)
- C: 0.312 inches (7.9 mm)
- D: 2.500 inches (63.5 mm)
- P: 2.240 inches (56.9 mm)
- R: 0.938 inches (23.8 mm)
- Shell Size 5:
- A: 2.800 inches (71.1 mm)
- B: 0.750 inches (19.1 mm)
- C: 0.375 inches (9.5 mm)
- D: 2.406 inches (61.1 mm)
- P: 2.140 inches (54.4 mm)
- R: 0.938 inches (23.8 mm)
These dimensions are based on Glenair’s standard specifications for D-Subminiature backshells.



