It's a Super-Tweeter!
The $2000 (USD) Prestige ST-200 super-tweeter has a vapor-deposited gold 25mm dome driver that has a -6dB downpoint at 54kHz (and only -18dB@100kHz). The two drop-in connectors on top establish crossover (14kHz, 16kHz, abd 18kHz) and sensitivity (89.5dB, 90.5dB, 92dB, 93.5dB, and 95dB). It integrated so seamlessly with the Glenair that I was initially convinced I was hearing only the concentric driver.
I suspect Art Dudley would kill for a Glenair/ST-200 combo—and I'm not sure but that it wouldn't be me he'd have to bludgeon to get to them.