HoMedics Deluxe Wrist Manuel D'instructions page 38

Recommended separation distances between portable and mobile
RF communication equipment and the device.
The device is intended for use in an electromagnetic environment where radiated
RF disturbances are under control. User can help prevent electromagnetic
interference by keeping the device at a minimum distance from portable and
mobile RF communications equipment (transmitters). Below table details the
maximum output power of transmitter:
Rated maximum
output power
of transmitter
W
0.01
0.1
1
10
100
For transmitters rated at a maximum output power not listed above,
the recommended separation distance d in metres (m) can be estimated using the
equation applicable to the frequency of the transmitter, where P is the maximum
output power rating of the transmitter in watts (W) according to the transmitter
manufacturer.
NOTE 1 At 80 MHz and 800 MHz, the separation distance for the higher frequency
range applies.
NOTE 2 These guidelines may not apply in all situations. Electromagnetic
propagation is affected by absorption and reflection from structures, objects
and people.
Separation distance according to frequency of transmitter
150 kHz to
80 MHz
Not Applicable
NA
NA
NA
NA
NA
m
80 MHz to
800 MHz
d = 1.2 √P
0.12
0.38
1.2
3.8
12
37
800 MHz to
2.5 GHz
d = 2.3 √P
0.23
0.73
2.3
7.3
23