MA-170 audio amplifier by Kinter is commonly available online and is very useful for projects. However, the chrome knobs are very tempting for people to turn!

Once your project is finished, you may need to turn it on/off, or adjust the audio level, but rarely. The large knob pulls off easily, but the small knobs are more difficult and that still does not stop kids little fingers.

This cover prints in ABS or PLA. Remove the large knob. You can remove 2 or 4 of the front panel screws, place the new cover, then replace with #4 screws that are 0.5" or 0.75" long. If you prefer to leave the original screws, a couple of drops of GELL-style instant set (CA) glue works well, also.

There is a 4 mm access hole to press the power switch and a 6 mm hole to allow a small flat blade screwdriver to push into the slotted shaft and adjust audio power setting. OpenSCAD file is included, if you want to eliminate these holes.