Two-way radios offer numerous benefits for outdoor enthusiasts, making them a better choice than cell phones and other types of wireless communication devices in many situations. Here's a quick run down of some the advantages:

• Compact and light weight.
• Operate anywhere, no need to worry about "coverage."
• No service fees.
• Long ranges and excellent sound quality.
• Small power requirements.

Channels
FRS offers 14 channels and GMRS offers 23 channels. Quality FRS-only radios often support all 14 channels in their frequency band. GMRS/FRS radios typically support a combination of channels from each band for a total of 15 or more channels. In general, the more channels a radio offers, the higher its price.

The more channels you have to choose from, the greater your chances of finding a clear frequency (one that is not in use by people outside of your party). This factor becomes especially important in crowded areas such as ski resorts. In remote areas, busy airwaves are much less likely to pose a problem.

Interference-Elimination (also called CTCSS, Squelch and Privacy) Codes
Many two-way radios give you the option of using codes from the Continuous Tone Coded Squelch System (CTCSS) to divide each channel on your radio into 38 sub-channels. When you set a code, you filter out all broadcasts not also set to that code, and thus increase your odds of finding a chatter-free frequency.

Keep in mind that this feature doesn't actually protect your privacy. Anyone else tuned to your channel with their interference-code feature turned off will still be able to hear your communications. In addition, anyone who has chosen the same channel and code as you can still transmit to your radio.

Power Output
FRS requires a power output of half a watt and GMRS requires 1-5 watts (most two-way radios that broadcast to GMRS do so at 2 watts). Radios that broadcast on both frequency bands will automatically step power output up or down when switching between FRS and GMRS modes.

Range
Both FRS and GMRS radio signals travel by line of sight. This means that terrain, weather and other factors will often reduce any radio's maximum range in the field.

A two-way radio's power output also affects range. Since GMRS radios typically have higher wattages than FRS radios, they typically will have a greater range. Under ideal conditions, FRS broadcasts have a two-mile maximum range and GMRS broadcasts have a five-mile maximum range.

Scramble Codes
Some two-way radios offer scramble (or "eavesdrop-reduction") codes that prevent others from listening to your broadcasts. With the right equipment, however, these codes are relatively easy to crack. It's best not to consider any two-way radio conversation entirely private.

Calling and Paging Features
Many two-way radios have pre-set "calling" tones that you can use to grab the attention of other members of your party before you start talking. You can even set some models to vibrate instead of making an audible tone.

Design
The two-way radios offered by REI are compact, light and well suited for outdoor use. Most two-way radios are weather resistant but not 100% waterproof, so you'll want to keep them protected from moisture.
When choosing a two-way radio, make sure it's designed to suit your needs. For example, if you plan to use your radio in low-light conditions, go with a model that has a backlit display panel.

Scanning
A scanning feature allows you to cruise through channels in order to find the one that your group is using. You can also use this feature to quickly locate an "empty" channel for your group to use.

Channel Lock
This feature allows you to lock your settings in order to prevent them from accidentally getting changed as you go about outdoor activities such as skiing, hiking and paddling.

VOX
Many two-way radios have a button which you push first in order to talk. Models with a voice-activated (or "VOX") feature begin broadcasting automatically when you speak in the direction of the radio.

Batteries
Typical two-way radio units utilize standard AA or AAA batteries. Some models come with their own rechargeable battery packs. Most two-way radio units will operate for a full day of solid use on one set of new or fully charged batteries.

Many two-way radio users power their radios with rechargeable NiMH (nickel-metal hydride) or NiCad (nickel-cadmium) batteries. These batteries present a highly economical option, as they can be recharged hundreds of times using affordable chargers that plug in to standard household outlets. In addition, REI offers solar chargers that allow you to replenish NiMH and NiCad rechargeable batteries when you'll be in the field for longer periods.

Note: In general, the higher a radio's power output, the more quickly it will drain batteries. Some radio models have a feature that sends them into a low-power, battery-saver mode after a certain amount of time has elapsed between broadcasts.

Headset Jacks
You'll find some two-way radios equipped with jacks for microphones, headphones and microphone/headphone combos. If you plan to use those accessories, make sure the two-way radio you choose has the appropriate jacks.

GPS/Two-Way Radio Combos
Garmin, a renowned outdoor-instrument brand, has recently introduced two-way radio/GPS combos as part of their RINO (Radios Integrated with Navigation for the Outdoors) series. These sophisticated devices offer full GPS and two-way radio functions. In addition, RINO units provide peer-to-peer positioning. This powerful feature allows you to broadcast your location information over the airwaves and have it appear on other users' screens.

Compatibility of Radios from Different Manufacturers
Any two radios that broadcast on the same frequency band (FRS or GMRS) and support the same channels will work together. Keep in mind that in order to get full use of a radio's features, you'll need another radio with the same features. It makes sense to purchase two-way radios in pairs.