Experience nearly every variety of adult pleasure out there with the Vac-U-Lock modular system - a collection of snap-on. sex toy attachments for secure. comfortable strap-on intercourse! Your lover will beg for more when you lock and load the 8â Realistic Cock and Balls attachment for your leather harness. Simply connect the lifelike. textured. veiny penis with tip and go all night long - from the front. from the back . . . whatever gets you off!