Reviewed by Martin J Quinn
January 2019
A new player has arrived on the scale modeling scene.  Black Cat Models from France bills themselves as "...specialists of CAD design, we use the best available softwares and printers to produce a complete range of kits and accessories of unequaled precision and quality at the present day."

One of their first releases are a set 3D printed 20mm guns in 1/350, set AC350001a, "20mm Oerlikon Mk4/0 Standard shield".   20mm Oerlikon guns were widely used by the US Navy in World War II.   This set from Black Cat Models will allow you to upgrade the kit 20mm guns found on your model ships.

Click to enlarge images
The packaging is a plastic clamshell container, with the 3D printed runner containing the 20mm guns secured to the bottom of the packaging with thick double sided tape.   This prevents the runner from moving during shipping.  However, I did find it that the runner is so well secured to the tape, that I had difficulty removing it from the package.   As to avoid breakage while taking photographs, I left them affixed to the tape.

There are 12 guns in the package.   The detail on the guns is very good.   Each 3D printed gun is a complete 20mm gun - with the pedestal, the actual gun, gun shield, magazine, shoulder rests and a gun sight.  All you'll need to do is paint and install, after removing it from the runner. 

Close ups of some of the parts details.
There are no instructions in the box, but the packing directs you to the Black Cat Models website.   There, on a data page for the particular item, you will find instructions on how to remove the printed supports that are part of the 3D printing process.
These 3D printed 20mm guns are very well done.   The print quality is first rate, with excellent details.  I'm especially impressed with the shoulder rests and gun sights. 

This is Black Cat Models set AC350001a, 20mm Oerlikon Mk4/0 Standard shield. . They retail for about $9.50 USD, and are available directly from Black Cat Models.   Highly recommended.