The Production Guide
Writer's Guide

8 WEAPONS

In the case of an alien intruder or captive who offers violence, the need to preserve him alive is even greater, since he may provide invaluable information about the nature of a hitherto incomprehensible enemy.

So the weapon that Alpha personnel carry with them is small, but multi-purpose - a TSLA. The initials describe the emissions from each of the four antennae; tranquilliser, stun, laser, atomic. There are selections on the grip for purpose and intensity. The first choice is a tranquilliser which will give an opportunity to prevent actual violence but still enable the user to talk to his victim; secondly, a neuronic stun will stop a man instantly and make him unconscious so that he will need medical attention to revive him; thirdly, a laser which will pierce known metals and matter and stop some alien spacecraft without actually destroying them; and lastly, the chain ray which engenders an atomic reaction in any matter that it strikes and so causes a totally destructive explosion.

The TSLA term was replaced with stun gun. The range of capabilities remained in series publicity, but we only see two, stun and kill beams.