International patent pending.Special design to hold a sanitary napkin in place. Therefore, no need to worry about it slipping out of place during menstruation. Has a swelling in the crotch as a fake male genitalia. Feel more comfortable in a gym or when you receive a massage.Here comes new underwear finally designed for FtM. * Size available M (26inches) , L (28 inches), XL(32inches) Pocket in the middle to insert artificial genital. Elastic strap to hold sanitary napkin. Sanitary can be firmly held. No slipping out.