6 Book NFT, Socket, Item

Book NFT only has one type of attribute which is the Resilience. Resilience determines the number of available concurrent leases.
Book NFT has sockets and items could be installed in these sockets.
Higher number of available concurrent leases means higher expected income from leasing.
One might acquire items that could be installed in the book NFT’s sockets by opening the loot boxes.
There are many items and items could help increase the attributes. Some items could be upgraded and have higher attributes.
Some items have level requirement and they could not be installed in the sockets if their minimum level requirements have not been reached.