Exafast NDS is a fast-setting Vinyl Polysiloxane (VPS) impression material developed for improved accuracy, increased productivity, and maximized patient comfort. Exafast uses a patented hydrogen scavenger formula, a "non-gassing" impression material that may be poured immediately. Also, it is hydrophilic, so it flows uniformly over moist surfaces for more accurate details, and penetrates the smallest cracks in the oral cavity.