Taking hands-on play to the next level, the Knuckle Up accessory will delight you with its novelty, functionality, and its undeniable ‘cool factor’. The Knuckle Up is compatible with all Vac-U-Lock attachments (we carry a few of the 100% silicone Vac-U-Lock toys in our store, sold separately). The unique handle allows you to grip the toy in a way that may be less tiresome on your wrist when playing with a partner.

When using a Vac-U-Lock toy with the Knuckle Up, don't forget to add some corn starch to the hole in the toy before inserting the Knuckle Up-- it will be a lot easier to remove the toy later!