Unbranded cordless spray gun using Makita batteries!

I know Wagner will make cordless spray gun soon using Bosch batteries and I was googling it but I found something different, an unbranded cordless spray gun using Makita batteries. Are they allowed to make an unbranded tool using Makita batteries or batteries from other brands?!

18V Spray Gun Cordless Compatible Makita’s BL1850B BL1860 BL1860B Professionals 6973691281659 | eBay

They aren’t the only game in town. Graco reps the DeWalt battery….

fyrfytr998 wrote:

1 hour ago, fyrfytr998 said:

They aren’t the only game in town. Graco reps the DeWalt battery….

 

I know Graco and also they use DeWALT batteries, before they adopt DeWALT batteries they had 18V and 28V cordless airless sprayers. And this is not the only cordless tool they have that works with DeWALT batteries. They have 60V Flexvolt cordless sprayers as well, and also a 20V cordless tool for Drywall Installers. Also the photo you provided is only for water based paints, they have another model “Ultra Max” I think it is called, which can be used for oil based paints as well.  

fyrfytr998 wrote:

2 hours ago, fyrfytr998 said:

They aren’t the only game in town. Graco reps the DeWalt battery….

 

But that was not my question, Graco uses DeWALT batteries with an agreement between both brands, here an unbranded tool uses Makita batteries, and I am trying to understand the legal status of this issue.