Ultra thin lens cap for Canon RF 28mm F2.8

thingiverse

As a ultra small lens for RF cameras, the lens cap of the RF 28mmF2.8 is not small enough, as thick as 8mm make it extrude too high. here I created one just 3.4mm to make it more compact.You need to get two springs with 2.8mm diameter and 12mm long. you can find one in an used electronic igniter. use a 17mm long iron wire to fix the spring in position.