SWR Meter
Bird Watt meters are the best because their percentage of error is very low, if I recall its 10% or less. However once you obtain the power forward reading you have to unkey your mic, rotate the slug in the front of the watt meter then transmit again to read the power reflected spec then compute your SWR. When used continuosly attached to a rig most guys just keep it on reflected power mode because most transmitters have a transmit power forward meter built into them. An increase in reflected power is easily noticble.
These days I use a Daiwa hf watt meter with a VHF/UHF converter. Two things I like about the Daiwa's is that they can be illuminated and are very easy to read. To obtain the SWR you simply transmit and obtain the power forward and the power reflected readings simultaneously via two needles that over lap to indicate the SWR. Believe Daiw's are rated at 20% or less. For amateur daily monitoring I would use a Daiwa, though delicate they are very easy to use and I don't own a Bird.
Berfore I retired I used a Bird watt meter everyday for years, they are durable, accurate and reliable. For commercial installations and preventative maintenance I would use a Bird watt meter. I once compared the Birds and the Daiwa's watt meters, they provided identical readings.