A lipstick-sized plastic disposable injector full of trauma-treatment nanites. It's got two charges left.
It weighs about 100 grams. It is a healing injector. You have no idea what it might be worth.
Can be bought from Meds 4 Less or from Sargo's Discount Warehouse. Also drops from Propecia in the Crack Mansion, or (uncommonly) scavengable from the cardboard box on the second floor's south-easternmost room.
Whend, provides an instant boost of health.