Keep your teeth gleaming with the STYLSMILE Whitening Gel Syringe Refills. The convenient syringes contain a boost of PAP (Phthalimido-Peroxy-Caproic Acid) that works to target the look of dullness, encouraging a pearly-white gleam. Three different causes of tooth discolouration are focused on, allowing the teeth whitening kit to be precise and thorough. Free from Peroxide and non-UV. Use with your STYLSMILE Whitening Boost Kit.