I designed this for a guy at work who needed a mount for a 9VDC battery and a panel mount toggle switch (7mm thru-hole). It is sized to perfectly fit an energizer battery. The battery installs upside down to keep all of the wiring to the switch and terminals on the bottom. In my application it was mounted to a surface on its side.It turns out there are slight differences in size in 9V batteries. He was using a Duracell industrial cell that was slightly larger so I printed them scaled up 5% in X and Y. Printed at 0.2 or 0.3 thickness 2 perimeters, 40% fill. The retainer snap is printed without support in air. It could stand to be a bit more aggressive (wider).