Don't know the part number of this one, but, you can see the construction.
It is a modular type, probably more expensive to build.
Its not sealed in the front at all, as Mangozac said there is a round flat silicone seal at the very bottom of the actuator shaft.
The LEDs in the front are sealed with clear silicone. The the polycarbonate/stainless steel actuator is in front of that. Spring on the plastic actuator shaft.