Doc Johnson Vac-U-Lock 6â   UR3 Cock Attachment. It's hard to imagine more lifelike dongs than Doc Johnson's Ultra-Realistic UR3 Dual-Density Cocks. These pieces are molded directly from a real cock- so they feature genuine detailing including plush balls, distinct veins, and bulbous heads. The Realistic UR3 Cocks were developed with a groundbreaking UR3 dual-density formula. They are formed with two layers: hard on the inside and soft on the outside, for the most authentic experience on the market. They even warm to the touch and recover their shape just like a real cock! Vac-U-Lock attachments can be paired with your favorite Vac-U-Lock harness or accessories for hours of rigorous play. Proudly made in America. Phthalate-free TPE with Antibacterial Sil-A-Gel formula. Works with all Vac-U-Lock Harness Systems and Accessories. Total Length: 7.3â  , Usable Length: 6â  , Diameter: 1.7â  , Insertable Length: 6â  .