Introduction: Red Dot Sight Replacement Lens Cover

Some time ago I misplaced one of the lens covers for my Tasco 30mm Red Dot sight. I searched for a replacement and found that they are very difficult to find - or you can pay $10-15 each for upgraded replacements with flip-up and see-through features (which I don't care for).

So - I made my own using the cap from an old prescription medicine bottle.

Tools & materials:

  • 70 mm x 30 mm pill bottle
  • razor knife and a steady hand


  • black paint
  • 30 cm of paracord
  • drill and bit sized same diameter as the paracord
  • cigarette lighter

Step 1: Cut Carefully!

Inside the pill bottle lid are 5 small nubs that normally lock into guides on the bottle's body. Shave them off flush using the razor knife, leaving a round 38 mm inside diameter (ID) cap.

Actually you can stop here, the cap will now fit over the 38.5 mm outside diameter of the sight body.

Or - you can do a little more...

Step 2: A Little Bit of Aesthetic and Functional Improvement

I painted the cap black on the outside (not the inside as that would likely change the fit from "snug' to "impossible"!)

Then I drilled a hole in the bottle cap the same size as my paracord's diameter, inserted one end of the cord, and used a cigarette lighter to seal the end of the cord, which also effectively created a small hard plastic knot on the "inside" of the cap which prevents the cord from pulling back through.

I then did the same thing with the remaining original lens cap I still had so that the two caps are attached with about 30 cm of cord between them.

This setup serves two functions:

  • Keeps the caps from getting separated
  • Allows me to pull them off and leave the cord wrapped around the mounting base of the Red Dot sight where they won't get separated from the rifle and lost.