A regeneration system for a work machine may include a power source configured to provide a variable power output. In contrast to previous single-piece inserts, the new inserts provide much more compact packaging for shipping but can be assembled quickly just before installation. The panel and valve sheet can be arranged so that the vent openings of the panel and the vent openings of the valve sheet are configured to align with one another for a period of time during deployment of the airbag.