The MFJ-1713S is the SMA connector version of the MFJ-1713.
5 ½" radiator is similar to the longer MFJ-1715S except for gain on 440 MHz. ¼ wave on 440 and efficient loaded ¼ wave on 2 Meters.
Both antennas are factory tuned for lowest SWR. Have Hi-Q, low loss construction to give maximum radiated power. Great for portable, mobile and rugged hamfest use.