The rugged Proof-Case for Palm Aircraft De-Icing/Anti-Icing refractometers is waterproof, crush-proof, dirt-proof, dust-proof, drop-proof, rain-proof, snow-proof, sink-proof – even goof-proof. It is perfect for providing an additional layer of protection when using your Palm Abbe in demanding environments or when you just want to know that your instrument is safely stored. The case has a fitted foam insert that cushions the Palm Abbe in the event of rough handling. Two heavy-duty latches secure the lid against an integral O-ring providing a waterproof seal to 100 feet (30.5 meters) under water.