Take-Home Patient Kit: (8) 1.2 ml syringes, (2) universal trays, (1) tray case 16% Carbamide Peroxide Syringe Daytime use: Wear 4-6 hours, once per day. Nighttime use: Wear 8-10 hours, once per day. PRO-SYS® Professional take-home whitening kit delivers a high-performance system for a more radiant smile. Available in your choice of carbamide or hydrogen peroxide formulas, PRO-SYS® supports a wide range of uses. To eliminate sensitivity, PRO-SYS® contains potassium nitrate and its water-based gel keeps teeth hydrated.