I found out who makes those parking meters around Denver and they have a
good bit of information on the internet.
http://www.ipsgroupinc.com/resources/brochures/
I still need to post an ad on CL asking for "used parking meters"
Also...
GSA has an Ultrasonic Particle Generator for sale, it's $102 dollars right
now, ends tomorrow.
https://gsaauctions.gov/gsaauctions/aucitdsc/?sl=81QSCI17093017
-Nick