Have a pair of walkie-talkie handset two-way radios? Let's say you only wanted one of them to be mobile, and you wanted the other to be stationary. The stationary one would work best if hooked up to larger speakers somehow, so you can always hear the chatter on the other end, and as loud as you need it. Well, with this little hack, you can easily take out the installed speaker in one of the radios and replace it with a 3.5mm audio jack. Then you can hook it up to virtually any speaker!