Rit Proline SunGuard Treatment Powder 1lb UPF 30 - Covering up with a t-shirt may seem like complete sun protection. But did you know you're not really shielding yourself from the sun's damaging UV rays? The average white cotton t-shirt offers just UPF 5 protection - a level that dermatologists would find inadequate. Enter SunGuard: an easy-to-use laundry aid that washes UV protection right into clothes. SunGuard boosts the UPF protection of a white cotton t-shirt from just UPF 5 to UPF 30, blocking more than 95% of the sun's harmful UVA and UVB rays. All you need to do is add one package of SunGuard to a load of laundry and UV protection will be washed right into your clothes, lasting up to 20 washings. This package contains 1 pound of SunGuard treatment powder.