A clone of https://he.aliexpress.com/item/1005006828275284.html

For $5USD you can buy it instead.  But I rather like this one.

BOM

• Heater - https://he.aliexpress.com/item/1005006954619853.html
• Plug Socket - https://he.aliexpress.com/item/33041079377.html
• A bit of wire
• A soda can
• tin-snips
• some clear plastic for the window
• Glue (any)

Steps:

1.  Print
   1. One of each part
   2. PETG
   3. .4mm nozzle
2.  Solder the heater to the wires.
   1. Tip, shape the wire into a hook, then hook through the holes
   2. use lots of solder
3. Solder the wires to the plug socket 
   1. order/polarity does not matter
4. Cut a soda can open, and make two heat sinks/spreaders from the can
5. Peal the sticker off the back of the heater and paste it to the heat-sink (soda can)
6. use a screw to punch a hole through the aluminum and screw it into two of the screw posts.
7. Glue the Window cup, into the “Top” from the “inside”. 
   1. try to line up the slots, to make it nice.
8. Glue the Top and Bottom halves together.
9. carefully fill the box through the 12mm socket hole, with the desiccant beads.
   1. do this over a box or pan to catch the beads that don't go in. 
   2. this is tedious, take your time
   3. Leave about a 1CM empty at the top
10. gently push in the excess wire, into the body
11. glue the socket in
12. use the Window-Template to cut a clear circle of plastic from any clear plastic.  
13. put a few beads into the window cup, then glue the window shut. 

OnShape:

https://cad.onshape.com/documents/bc19d7d949b76b3ded0420cf/w/f89b9b3ef9841d41e9fc80bd/e/7c9222c1814f32faa02392cd?configuration=Length%3D0.15%2Bmeter%3BPerforationDiameter%3D0.0022500000000000003%2Bmeter%3BPlugDiameter%3D0.012%2Bmeter%3BWidth%3D0.06%2Bmeter%3BWindowDiameter%3D0.03%2Bmeter&renderMode=0&uiState=68eba38c6342882b2a6c1dab