Hi all, I thought I would share my case with the community, it is a variation on a theme but it has worked well in the few tests I have done. The case is a Lock & Lock rectangular 180ml container (HPL805): http://www.reallyusefulproducts.co.uk/uk/html/onlineshop/locklock/rec_hpl805.php The inner foam housing is 2 layers of EFP30 Polyethylene closed cell foam sheets 20mm thickness. One is supporting the AudioMoth the other is cut to fit the AudioMoth inside : https://www.easyfoam.co.uk/closed-cell-polyethylene-foam.php Then over the hole drilled for the microphone I have used Buzzer Waterproof Acoustic Membranes brought on Alibaba: https://www.alibaba.com/product-detail/Buzzer-Customize-Size-Black-Waterproof-Acoustic_60812354593.html?spm=a2700.galleryofferlist.0.0.6c233527JZ969G&s=p The box remained watertight under a tap at full strength, focused directly on the acoustic membrane, so I am hoping rain at an angle won't pose too much of an issue. Only thing I am a bit nervous about is the glue holding the membrane, if it will withstand tropical humidity. I will keep everyone updated. Cheers