BN-273A/BN-273B/BN-273C/BN-273D/BN-273E/BN-273L/BN-273R
| Part Number | Resonator | Ball | Sensor | Additional Info |
| BN-273A | 21 1/2" | 2 5/8" | ||
| BN-273B | 18" | 2 1/4" | ||
| BN-273C | 18" | 2 5/8" | 1 sensor | sensor in front right pipe |
| BN-273D | 18" | 2 1/4" | 1 sensor | sensor in front right converter |
| BN-273E | 21 1/2" | 2 5/8" | 2 sensors | |
| BN-273L | left converter w/neck only | |||
| BN-273R | right converter w/neck only |
measurements required: resonator length; outlet ball size; number of sensors