Sony's ECM-77 has been a broadcast standard since it arrived on the market sometime in the mid 1980's. It's both very good sounding and has a reasonably low noise floor for a miniature electret mic, and has stuck around for a very long time. Only really being equalled in more recent years due to the proliferation of Sanken COS-11 and DPA 4060/61/71 series lav mics. The latter of which are very much the lavs of choice for theatre, film and TV productions. Despite that the ECM-77 can be seen on pretty much every news broadcast over the last 20 years, both in the newsroom and out on location.
It's proliferation also means that second hand ones can be picked up quite reasonably priced (under £100!) which makes them a very good low cost mic to upgrade to if you have the baseline Sennheiser G3 or Sony UWP-D wireless systems; on which the bundled mics are pretty terrible.
This is a well built mic that has withstood the test of time in the broadcast industry. The cable is quite thick for a modern lav mic; not much different to a Sanken COS-11 but not as discreet as a DPA, as such, hiding it under lightweight, tight fitting clothing could be problematic, but no more so than a COS-11.
They are only really supplied in black and grey though so the intended purpose could well be read into there. As mics intended to be hidden, like the DPA's are supplied in a variety of colours from black to white and all the skin tones in between.