I mean, it's not an item, but there is the Lifemate NPC trait (DMG2 p.159): gives a constant Status type effect, Sending 1/week and Shield Other 1/month. Not worth LA +1 though.

I have looked for an item like what OP is seeking in the past, and was also unable to find it. Pretty sure there were options in earlier editions, but just not sure about 3E.