Downhole tools, including downhole valves, may actuate via a pressure differential created across a shifting element having one or more pressure surfaces isolated from fluid, and fluid pressure, flowing through the interior flowpath. Embodiment downhole tools of the present disclosure may actuate in response to, among other signals, fluid pressure in the interior flowpath of the tool and fluid pressure communicated to a pressure surface of the shifting sleeve from the exterior of the tool. Certain embodiments may also have an outlet connector whereby fluid pressure from the downhole tool may be communicated to its exterior. Isolation of the shifting element from the interior flowpath may be accomplished using a frangible, shiftable, degradable or other members which may be moved from a closed state to an open state in response to fluid conditions in the interior flowpath.