[Ratters]

Those items you're looking for are pretty hard to find. They're specific to a less than common item not typically found or imported here

I would send an email to some of the og airsoft retailers, Den Trinity, WGC and Redwolf come to mind, pretty much any website store that carries and has a supply line to inokatsu products

Possibly there's an option to contact Inokatsu directly but the site may need translating and they may or may not ship outside of Japan unless your a registered distributor

Good luck with your search