Lego Compatible Backpack Attachment

Just a fun modification and no real world use, modeled based on real Lego with 4.8 mm studs and 8 mm spacing

should be printed flat on the side without studs, no supports needed

I replaced the holes with Lego-like studs and changed the size so that Lego bricks and similar building blocks would fit to the sides,

left the original fillets therefor putting Lego brick on the edges will leave a very small gap