$20 4oz aluminum tube perimeter frame: Eberlestock endo-g frame

https://eberlestock.com/products/endo-g-type-internal-frame?wickedsource=google&wv=3.1

Pics:

https://ibb.co/xhxcbqX
https://ibb.co/HHPS5hh
https://ibb.co/rGcdtct
https://ibb.co/7KTXRnF

I just ordered 2 of these. The past pic is next to the frame from a m/l Durston 40. You can see it’s a couple inches longer and it’s a tube while the D40 has a hoop. The Eberlestock frame is stiffer and 1 oz heavier. I wasn’t able to bend it easily.

Seems like a very attractive price and size for internal frame MYOG backpacks.

Has anyone else purchased and used this?

I’ll report in when I build a pack around it.