Master Series Silicone Collar Slave Black O/S. Claim your submissive with this high quality silicone collar from the Master Series. This comfortably slender silicone collar is adjustable. to ensure a snug fit. The collar makes the ultimate statement. with the word SLAVE simply stated on the front in raised white silicone letters. Adjustable notch closure in the back. Ideal for a night out. or a naughty BDSM session. Measurements 17.5 inches in total length. 0.75 inch wide. Materials Silicone. metal. Color Black.