Edmund Optics: Athermal imaging lenses
The Techspec Cw series is a range of splash-proof fixed focal length lenses that meet IEC ingress protection ratings IPX7 & IPX9K. They do not require additional protective tubes, allowing for more compact and lightweight imaging systems. The special focus mechanism and fixed apertures also make them much more stable than ordinary lenses against vibration and shock.
Multiple O-rings prevent water from entering the lens. The lenses further feature a specially coated hydrophobic protection window, which prevents water droplets from adhering to the lens.