Add style to your swim wear with the prAna Sirra Bikini Bottom. Made from knitted fabric, it is flexible and comfortable. A flattering front waistband provides adequate support throughout the day, lending an excellent fit. Its side seam features a shirring detail that enhances your overall visual appeal. Its midrise and standard leg cut improves wearability. A moderate seat coverage imparts modesty and added comfort. UPF (Ultraviolet Protection Factor): The protection given to the skin by a fabric is indicated by its UV Protection Factor (UPF). Specifically designed to block the sun's harmful UV radiation from damaging the skin (widely known as UVA/UVB/UVC rays). Moderate seat coverage.