Vac-U-Lock Modular System Double Penetrator Dong. An attachment for the Vac-U-Lock Line, This is a vinyl rubber double penetrator that is designed to stimulate anal and vaginal. Both shafts are about 6 inches long. The thicker one is 1.5 inches in diameter while the thinner one is 1 inch. Phthalate free, non-toxic materials: Sil-A-Gel, PVC. Recommended lubricants are water base. Length: 5" - 6" Width: C 1.5" - 2" Color: White. Vac-U-Lock is a US patented harness attachment system. It was the first of its kind 20 years ago when it was developed and still continues to be the strongest brand name in harness systems today. With countless attachments, plugs and full harness systems, Vac-U-Lock is an all-encompassing modular sex system that gives the user the ability to pair different attachments with different harnesses and Vac-U-Lock plugs to create infinite possibilities. Vac-U-Lock Modular Sex System Attachment from Doc Johnson Novelties the Great American Toy Company 2011 Catalog page 105.