Filtered Air Face Shield

1/14/25 update: I have posted an improved filtered air supply for this face shield (https://www.thingiverse.com/thing:6906832) . The back piece with the rubber band has also been improved to hold the rubber band better. The new design is (rear rubber short2).
This is an upgrade of an earlier face shield I designed. This mask delivers filtered air to keep the shield from fogging as well as supplying a flow of filtered air (99% of 0.3um particle sizes) over the eyes and mask. Filters used are cut from KX Filter melt-down polypropylene electro-charged fabric. Once a small square of filter is cut, I melted a small hole in the middle for the bolt that sandwiches the filter between the lid and cover. The 12 volt dc brush-less fan is from DFRobot (FIT0241). A switch and four double AAA battery packs wired in series supply the 12 volts dc. Once the fan output is placed in the holder in the box you will need to drill a bolt hole and add a bolt to secure the fan (see picture). The bolt can't be