The ZOOM range of socket modems from Siretta are available in four variations.-ZOOM-N-GPRS (without GPS) 8968140. -ZOOM-G-GPRS (with GPS) 8968143. -ZOOM-N-UMTS (without GPS) 8968147. -ZOOM-G-UMTS (with GPS) 8968156. . Whats so special about ZOOM socket mo