• 12VDC or 24VDC selectable output. • 4 amp of continuous supply current. • Transformer requirements: - 24VAC/100VA or 28VAC/100VA for 12VDC output (Altronix Model #T2428100). - 28VAC/175VA for 24VDC output (Altronix Model # T2428175). • Filtered and electronically regulated outputs. • Short circuit and thermal overload protection. • Built-in charger for sealed lead acid or gel type battery backup. • Maximum charge current .3 amp. • Zero voltage drop upon transfer to battery backup. • AC input and DC output LED indicators.. • AC fail supervision (form "C" contact rated @ 1 amp 28VDC). • Low battery supervision (form "C" contact rated @ 1 amp 28VDC). • Lifetime Warranty.