Aquasonic 100 Ultrasound Transmission Gel Features: * Acoustically correct for the broad range of frequencies used * Completely aqueous, will not stain clothing or damage transducers * Unique "can't be copied" formula is hypoallergenic, bacteriostatic, non-sensitizing and non-irritating * No formaldehyde * Not a spermicide * Used and recommended by leading manufacturers of medical ultrasound equipment worldwide