These two items can either be glued or screwed into the rectangles on the inside of the lid for the Milwaukee Rolling Toolbox. I have tested up to the 5.0mAh battery in the front portion and it clears the front of the case when it closes. I have printed them in PLA and PETG at 20% infill. Had them break with 4 batteries in when I let the lid fall by gravity. Reprinted @ 50%, no issues. Print with supports.