Garmin 18 Deluxe PC and Serial Interface GPS Sensor with nRoute and City Select Navigation Software A simple, convenient, and inexpensive way to turn your PC laptop into a personal navigator GPS sensor bundled with nRoute and City Select navigation software that automatically guides you with turn-by-turn directions and voice prompts 12-parallel-channel, WAAS-enabled sensor/receiver just 2.4 inches in diameter with an integrated magnetic base Connects to your PC via a CMOS-level, DB-9-pin serial interface with 6.5-foot cable and a 12-volt cigarette lighter adapter Waterproof to withstand immersion in 1 meter of water for 30 minutes