Howard Leight Earpro tactical 2way PTT setup. $40.

[Moab]

All sellers of this appear to get 5 star reviews. This is the best price I could find. Basically the cheapest form of two way radio coupled with enhanced ambient sound earpro. So in a bug out you can be firing your rifle and communicating with others via two way radio.

Basically gives you a connection between earpro and your two way handhelds. Listening is provided covertly with the Howard Leight Impact Pros input jack. So your listening inside the earpro - combined with the enhanced ambient sound listening of your earpro. Mic via the provided boom mic. And a complete K1 connector for Kenwood or Baofeng. They also sell other versions for Walker earpro and other PTT connectors. 

Howard Leight Earpro not included. But they have been around for decades, are great quality affordable earpro and run around $50. Or knock off versions on AliExpress are $20. 

Just found this amazing item on AliExpress. Check it out! 
$39.99 | HEARGEAR External Mic Kit with Tactical U94 Ptt for Howard Leight Impact Sport Electronic Earmuffs Tactical Airsoft Shoot Headse
https://a.aliexpress.com/_mOIaJik

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[NT2C]

Wonder how it'd fit my Walker earpro?

[Moab]

Wonder how it'd fit my Walker earpro?

They make models specifically for Your walkers. Let me find a link.

[Moab]

This is the one for Walker Razors. But I did not search for best price, number sold or other Walker models.

Just found this amazing item on AliExpress. Check it out!
$45.24 | Tactical Headset Microphone Y-Line Kit for Walker's Razor Electronic Earmuffs with Tactical U94 PTT for Baofeng Walkie-talkies
https://a.aliexpress.com/_mrHxTrO

[Moab]

They are called Y line kits. At least on AliExpress.

I was looking for a diy set up. You can find the PTT part. But the boom mic part is hard to find. There is a US company called Tigrett(?) that sells a similar cable set. But no boom mic and is $35. This unit is seems way better. 

The real deal ( I forget the famous brand name that works with helmuts) is very expensive. This is much more doable financially. Especially considering you need at least two. If not more.