Vac-U-Lock - F- Machine - Black The F- Machine delivers superior power and endless deep pleasure. The strong machine's adjustable thruster arm can be angled to give you what you want in all your favorite positions, while four strong suction cups at the base keep it securely in place no matter how hard you play. For players who like it hard and fast, this versatile fucking machine offers variable speed to pound your holes at up to 195 strokes per minute. Created exclusively for use with attachments in Doc Johnson’s patented Vac-U-Lock line, The F- Machine accommodates any Vac-U-Lock compatible attachment in your collection and available through Doc Johnson.