The Darian radiation suits are spacesuits from the Catherine Schell film Moon Zero Two (1969). Note the two helmets are slightly different; one is a spacesuit helmet from the UFO series (actually made for Gerry Anderson's film Doppelganger).
On the left is the Moon Zero Two helmet (note the raised section at the bottom of the visor). On the right is the UFO helmet (note the crown section on the top of the helmet).
The door of the Darian cabinet that eats Lowry and the female mute is also seen on Thule in Death's Other Dominion
Both Alan and Paul have regular stun guns, without the slider. When Alan fights to free Helena, his stun gun has a slider. This was possibly in case a close up was needed when Paul cautions that they should use stun.
The large alien probe (studio prop) from The Last Sunset is seen as a fire
The Darian guns were originally the direction locators used by the Alphans on Retha in The Full Circle. They are seen again in A Matter Of Balance
When Koenig finds Helena, we see a close-up of her. Kara's legs are seen behind the Darian girl. In wide shot, Kara is in a different position.
Copyright Martin Willey.