Honeywell 2020 - Manual (Page 6)

Eye Safety Statement (LED)
This device has been tested in accordance with IEC60825-1 LED safety, and
has been certified to be a Class 1 LED device.
Radio Technology
Class II
CB Scheme
Certified to CB Scheme IEC 60950-1.
Solids and Water Protection
The 3820 has a rating of IP41, immunity of foreign particles and dripping
water.
The 3820i has a rating of IP54, immunity of foreign particles and sprayed
water.
Patents
Please refer to product packaging for patent information.