Ring of Blinking
You spend a standard action to activate it with a command word. It will typically have a caster level of 7, so it will function as the blink spell if cast by a 7th-level caster. In this case, 7 rounds. You may use a standard action to restart it, either after the duration ends, or while the effect is still in effect, in which case it will last another 7 rounds (overlapping, not stacking with remaining duration).
Ring of Invisibility
You spend a standard action to activate it with a command word. It functions as the invisibility spell. The ring typically has a CL 3, so it will be as though cast by a 3rd-level caster. For invisibility that means it will last 3 minutes (or until you attack or take a hostile action or other action that would cause invisibility to drop.) You may reactivate the effect as many times as you like by spending a standard action and speaking the command word.
