Self-powered for 90 minutes. The RPSP series is suitable for property management and institutional applications, and is designed using durable and lightweight high impact thermoplastic. Available in AC only, AC & DC, and self-powered versions. Self-powered for 90 minutes. The RPSP series is suitable for property management and institutional applications, and is designed using durable and lightweight high impact thermoplastic. Available in AC only, AC & DC, and self-powered versions.