tour audio systems for MRF?

[Ursula]

Hi all,

Thank you all who recommended videos online of MRF operations. We are
also interested in tour group audio systems that would help a group
touring the MRF be able to hear the guide. Does anyone have any
recommendations/experience? I've heard of Listen Tech, Eartec,
Williams Sound, and Earmark so far but I'm sure there are others. I'd
love to hear anyone's practical experience.

Ursula, City of Sunnyvale