Take-Home Bulk Kit: (20) 3.5 ml syringes, 10 refill boxes of 2 14% Hydrogen Peroxide Syringe Daytime use: Wear up to 15 minutes, once or twice a day. Allow a minimum of one hour between wear time. PRO-SYS® Professional take-home whitening delivers a highperformance 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.