Omega Lock

The Omega Lock is a piece of cosmic technology found in the Cybertron portion of the Unicron Trilogy continuity family.

Eons ago, the lifeforce of Primus was divided into the four Cyber Planet Keys and scattered across the galaxy. The Omega Lock is the device that the Keys join with to reawaken Primus's power.

Toys

The Omega Lock only appeared in toy from as an accessory that came with the Cybertron Primus toy. The Omega lock can hold the Cyber Planet Keys that come with the toys in the four slots on it and is needed to transform Primus.

From Teletraan I: The Transformers Wiki, a Wikia wiki.