Abstract: The invention relates to a one-piece sandal (1) injected in a single piece with a strap (2) placed on the side of the sole (3S), particularly non-slip, and of the insole (3P), particularly anatomical, however with freedom of rotation towards the front hook (4) where the male fitting (5) engages with the female fitting (6) of the strap (2), forming the strip in the format of the instep, thus providing a product having an innovative assembly concept, with non-slip sole and comfortable insole.