I have an HT that requires an antenna change to operate on 220MHz. But who grabs an extra antenna when they leave the house? This allows the extra antenna to be at the ready.
You just need to grab the right SMA connector (male or female), and screws that will work with your connector (I used 2mm self tapping SHCS, but #2 should work as well).
The author marked this model as their own original creation.