Zenitco's attention has been called to copies of their products produced, especially for the airsoft market, without their knowledge or agreement. They are willing to negotiate with those willing to contact them regarding such copies, especially not using the Zenit markings and they will be doing legal action who will not.
They are looking into licensing their products to any interested company, though they will need more convincing. Their message,posted on Facebook, can also be read below:

Attention everyone.

FAKE PRODUCTS. They exist. We will not mention any companies as we don't deem them worthy of this, but please watch out.

Zenit has not given permission to, endorsed, or supported any of the companies currently producing these copies.

Oh, and airsofters may also be surprised that most of these cost almost the same as the real thing (even after price recalculation) and still require modifications.

Real Zenit products are constructed out of aviation-grade D-16T strengthened aluminium alloy. Whatever the copy products are, our director was able to bend that metal just by squeezing it with one hand as you will see in the pictures. If you're getting fake products, at least get something better quality than what we've seen so far.

What we have a problem with is the fact these are produced WITHOUT our permission, using our markings, out of inferior materials, are NOT marked "for training/simulation use ONLY," and are made without any licensing from us. If used on firearms, these products pose a huge risk of damage or injury.

If the companies making these would contact us and reply or at least change the designs and not use Zenit markings, we could reach an agreement. At the moment, legal action against these forgeries is on the way.

Please, firearms owners, do not risk damage and serious injury by using forgeries of Zenit products on your firearms. We have seen people do this.

Stay safe everyone,

-Den

P.S. All thoughts and feedback on this issue will be considered, as we ideally would like to see a "PTS" line of Zenit products or (legally) license them to another company. However, some people inside the company still need convincing. Тем более если ваши аргументы изложить на Русском языке. Что вы думаете об этом, товарищи?