Check the listing for details. 40mm GOST to 40mm NATO Thread Adapter Kit for Russian Gas Masks NBC CBRN. Condition: New. Listed at 8.99 USD. Up for sale is a complete kit to convert your Russian 40mm GOST to fully use 40mm NATO Gas Mask Filters. Why buy/use this? Because most GOST Russian Gas Mask Filters contain asbestos, so do not use them! The 40mm NATO rated filters are more modern, have better availability, and better prices. So, modernize your Cold War Gas Mask and use abundant, cheaper, better modern NATO filters. This is a complete kit and it will come with the following (look at first picture): 1. Thread Adapter - To use a 40mm NATO Filter on a Russian 40mm GOST Gas Mask. This adapter will come in Gray or Black. 2. One Rubber Sealing Ring/Gasket - Gasket is installed inside the adapter to make a positive airtight seal with your 40mm NATO Filter. Gas Mask Adapters Disclaimer – You accept all these terms and conditions the moment you purchase an adapter. Due to recent communication with some customers, I decided that I needed to post this important statement and make sure that you, the buyer, fully understands and agrees to this before hitting the “BUY” button. I want to clearly convey that my gas mask adapters are offered as-is with no promise of performance or guarantee. When the buyer purchases these adapters, they assume all responsibility and risk when they use them in any circumstances. This is independent of the application the buyer is intending to use them, from cosplay, Halloween costumes or even for critical/dangerous applications. The buyer is responsible for any failure or accident when these adapters are used. Even the fitment cannot be guaranteed 100%. The only thing that I can promise is that they will be made to fit the specific specs or gas masks as shown in the Description. This is especially true when these adapters are used in old surplus gas masks which are being used way past their expiration date. These masks have degrading rubber, so no guarantees can be made as far as a good seal. These adapters are made via 3D printing and can be made from a variety of plastics, from PLA Plus, ABS to ASA or others. Because of this some areas might have to be trimmed after manufacturing. I do this before I ship out the adapters, but the buyer might need to do additional trimming when they are fitting the adapter to their gas mask. You agree that you are willing to perform the trimming with a box knife or a similar blade. This I cannot do beforehand since I do not have your specific gas mask. Thank you again for your purchase.