BN-337LB/BN-337RB
| Part Number | Neck Length | Sensor | Inlet/Outlet | Shield |
| BN-337LB | 14 1/2" | 1 sensor 1/2" below inlet; 1 sensor in middle of body | 2 bolt inlet, pipe outlet | shield under body & neck |
| BN-337RB | 13" | 1 sensor 2" below inlet; 1 sensor in middle of body | 2 bolt inlet, pipe outlet | shield under body & pipes |