This 3-piece kit comes with all the necessary pieces to attach your Astro/Alpha to any two antennas of your choice. Most customers use these on their mag-mount and handheld antenna of choice. Pictures show the connectors on all the antennas we currently have manufactured for us and manipulated. If you are in and out of your truck a lot or want to change antennas in the field, this is an excellent accessoryto save time.