Bolded plunger - as single one usually for paver or in a row for Hollow block and curbstones.
This system is normally used for avoiding welding cracks caused of the vibration. The connection between tamper head and plunger will be done with 2 or 4 screws and the position is fixed usually by 2 pins.
Additionally benefit is that „in case of" it will be very easy to exchange the plungers.
From our side - we prefer to use this system always as "single one" - The precise of our bottom unit (especially for Hollow Blocks) is in a tolerance that you can change the new plunger with assembled shoes on each cavity without polishing anything. Just bold the new one in! If you need spare parts you get in a very short time and do need to keep those in your stock. The weight of those parts is really less - so we can send cheap by air in each corner of the world.