Updated-11-7-20
This link is to Dan Johnson's build page where he describes in detail
how he built this rifle, check it out :)
Dan Johnson Build page.

  Today we have a scratch built Lost in Space Season 1 Laser rifle
Built by Dan Johnson.
The rifle features a powerful blue laser that Dan synchronized
with the Starling LIS laser rifle soundboard.

Take a look at the photos of this awesome prop and see video
of it in action, it takes me right back to the show:)

If you have any questions about this rifle,
please contact Dan Johnson at djohnson138@cox.net