The PVX-4141 and PVX-4141B are functionally identical high-voltage pulsers with the same electrical specifications, performance characteristics, and output capabilities. The ‘B’ suffix denotes a chassis or packaging revision — not a change in electrical design or functionality. Both models are interchangeable in any application. If you are replacing an existing PVX-4141 unit, the PVX-4141B is a direct drop-in replacement with no changes needed to your setup or wiring.