Our Thong has powerful protection with the slimmest silhouette! Our breathable, buttery soft microfiber with a mid-rise eliminates panty lines and leaks. Get minimal coverage that still includes our multi-layer Leak-Loc system. The Unders by Proof Thong features an ultra-thin, invisible leakproof core in the gusset, designed to fit and feel like your favorite underwear with built-in period protection to help keep you dry, comfortable and protected. Even better? Unders by Proof are machine-washable and easy to care for. Reusable undies are a great addition to your period regime, or as a replacement for disposable period products. Unders by Proof has you covered.