Master Series Thorns Spiked Wooden HumblerKey Features: Implement of Pain and Control: Keep him on his knees with this humbler that attaches to the scrotum and hooks behind the thighs. Curved Wood: The smooth, dark, Beechwood is ergonomically curved to fit around most thighs as it keeps them relatively immobile. Adjustable Pressure: Turn the knobs on either side to tighten or loosen the screws and add or remove pressure, effectively locking them in place when tight and making it removable