This is a High Quality version of a 5mm LED Chrome Panel-mounted Bezel.
These bezels are the very same bezels used on my MAXes. They are machined to accept a standard T1-3/4 (5mm) flanged LED. The machining provides a close tolerance for the flange in the barrel of the bezel, but stops short of allowing the flange to pass through the front. That way, you can insert the LED and push it forward with confidence that it won't fall out. The bezel barrel is extra long for those thicker panels that some of us use.
A soft, but expansive black rubber stopper closes off the back for a tight fit that secures the LED tightly into position.