these have the standard Nato 40mm threads, these have an expiration of March 2015. They are all new in the plastic packaging still sealed unused. Example: http://www.armygasmasks.com/Current-Issue-U-S-Military-C2A1-NBC-Filter-p/aaagas-157.htm
Looking for $45 Shipped EACH, or 3 for $125 shipped.
i Accept Paypal + 4% or USPS money order.
i have a lot of these!!