My submission is a bit unusual in that it is not just for replacing a lost or broken battery cover, it is a design that replaces an original battery cover with a cover that adds functionality to the device it fits with.
In this case the device is a Utilitech FT-LOW1424-1 65-Lumen LED Flashlight. These flashlights are inexpensive and very common (at least here in the U.S.). They are carried by a large nationwide chain tool supply store which often issues coupons to receive the flashlight for free. This item can also be purchased through EBay and there is also at least one large hardware store chain in the U.S. that carries them.
My design replaces the battery cover with a cover that has features to allow it to mount onto a bicycle’s handle bars for use as a bicycle headlight. The lens can also be covered with red transparent self-adhesive film used for repairing automotive tail lights that is readily available at many auto parts stores for under $2.00 U.S. in a 5” x 7” sheet (enough to cover at least 6 lenses) and then mounted on the bicycle’s seat post and pointed rearward to act as a bicycle tail light to improve night time visibility.
Additional components required for the assembly besides the flashlight and the 2 printed parts are 2 each 6mm x 45, 50, or 55mm (depending on diameter of handlebars or seat post) hex bolts, 2 each 6mm washers, 2 each 6mm hex nuts.
Thank you for reviewing my submission!