Magicka Base

Description
When powered with Magic Essence, this structure provides a smaller shield than a House Seal, but with the added benefit of preventing any non-allied creature or player from passing through it. A single House can support up to 3 Magicka Bases at once. -- Directly from patch notes

Similar to the House Seal but with a smaller radius and the added bonus of protecting tames along with having multiple Magicka Bases

Quote
"Core equipment. No one could enter except allies after active this base. Cost Magic Essence. Each House can only owned at most three."

- In-game description