Sentinels Mark II
The Mark II Sentinels were constructed along lines similar to the Mark I, with increased capabilities in flight, mutant detection, armor, and weaponry. In particular, the Mark II had gas jets and steel tendrils in their hands that could emit a powerful knockout gas and/or entangle opponents. Mark II's could be controlled by a human being wearing a special cybernetic helmet.
The Mark II Sentinels, the most powerful in their line, were apparently able to adapt to almost any form of attack and counter it. If aware of the power they were being attacked by and given time to analyze it, they were equipped to self-generate a defense against it. Examples included scalding steam against the mutant Iceman, an adhesive coating to negate cosmic rays against the mutant Living Monolith, and the generation of certain vibratory patterns to negate the effectiveness of the android Vision's intangibility. The Mark II's were apparently able to adapt a defense against any attack even the hammer of the god Thor. Information on a defense was relayed to all fellow Sentinels and retained indefinitely.
The Mark II's could regenerate damage due to internal self-repair facilities and their own adaptability programming.
The adaptability of the leader of the Mark Il's, Number 2, was affected by solar flares so that it actually adapted into a mutant. It gained the power to create gateways capable of teleportation gates and registered as a mutant on all mutant-detection devices.