This is a basket that holds round basket-style coffee filters. Pushing down on the spring-loaded plunger shoves a paddle covered in the bluetack used to hold up posters into the top filter in the basket, and as it retracts, more often than not, it grabs just one filter so you don't have to stand there, partially awake, bleary-eyed and hating life as you try to get just one filter before you can make your coffee.

I used a compression spring with a wire diameter of 0.05", an outer diameter of .79" and a free length of 2", I also assembled the plunger using a heat-set brass screw in M3x10mmx5mm and a 10 mm M3 screw, but you could easily superglue that. I wanted the option to take it apart if I needed. You also need some poster tack to put on the plunger bottom.

I printed out the all blue test piece on 2 plates on my A1, but did the tan and brown variants each on a separate plates to better manage colors.