| Length of shell (after assembly) | 33.5mm (excl. the plug) | 
| Weight | 4.0g (BM25) | 
| 4.1g (BM35) | |
| 5.1g (BM44) | |
| Material of plug | High purity 24K gold-plated copper | 
Internal connecting material  | 
  Mixed conductor of OCC and silver-plated OCC  | 
Material of shell  | 
  6063 aluminium alloy |