You gain a number of levels of the Immovable ability equal to the item’s Tier.
A number of times per Long Rest equal to the Tier of the item, you can spend 1 Minor Action or your Reaction to anchor yourself in place, becoming immune to effects that would knock you Prone or move you against your will until the end of your next turn. This effect holds you in place relative to the local gravity field and thus can be used to temporarily stop you from falling, though it grants you no ability to move while suspended in midair. This effect does not protect you from impacts while you are anchored; if an avalanche hits you while you are anchored, you may not move but you’ll still take a significant amount of damage from the boulders striking you.
You can instead use this ability to anchor the enchanted item in place instead of yourself, which may have interesting applications depending on what it is, how durable it is, and how creatively you use this effect.