The Ultimate Intro Kit The Bundle of Everything 7 Best Intro Makers: Create Unforgettable Video Opening [BUNDLE] First Impression Kit. The intro set is perfect if you want to give period underwear a try and save some $$$5% off to be exact. You get 3 pairs of The Boxer Brief (To cut back on the wash days, give our other bundles a try!) What is The Boxer Brief? A comfy, mid rise boxer brief made from super soft recycled nylon. Our machine washable boxer brief period underwear is engineered for regular or light flow days, ideal as a standalone solution or reliable backup for heavy flow days. (psst.. we've made some really cool updates to the boxer brief like: an extended gusset, a pad shaped gusset to allow more absorbency and comfort, and a reinforced waistband)