PackTenna Mini 20m/10m End-Fed Half Wave Antenna with Banana Socket for Extensions.
This end fed half wave comes with about 31' of antenna wire trimmed to the 20m band. This allows for operation on 20m and 10m. Many have also used it on 15m but it has slightly higher SWR on 15. The end of the antenna wire is finished off with a strain relief loop and banana socket so you can add additional wire for a 40m wire element or even longer for 60 or 80m. Longer wire sold separately.