A very high quality GPS receiver by Polstar Technologies Inc which will give you a signal quickly from a cold start and a high number of satellites to enable you to keep an accurate position. The item is supplied with a car charger which will charge both the receiver and your PDA as well as passing the signal to your PDA.

High sensitivity for very weak signal acquisitions and tracking
Integrated powerful CPU, base band and RF front-end hardware in a SOC (System On Chip) design reduces the space and power consumption
Advanced IC technology allows total receiver cost saving
Allows the receiver to track up to 12 channel satellites
Fast TTFF for cold start, warm start and hot start
High performance firmware drives an excellent positioning speed
Serial communication channel with user selectable baud rates allows maximum interface capability and flexibility
Supports backup power to sustain internal clock
Suitable for notebook, PC, PDA and others
Optional USB cable, PDA connector
Accuracy:
Position: 5m without SA
Velocity: 0.1m/second without SA
Time: +1u seccond
Acquisition:
Cold start: 50 seconds (average)
Warm start: 35 seconds (average)
Hot start: 2 seconds (minimum)
Sensitivity:
Acquisition: -139dBm
Tracking: -152dBm
Dynamics:
Altitude: maximum 18,000m
Velocity: maximum 500m/second
Acceleration: maximum +/-4g
Navigation update rate: once per second
Serial I/O: series RS-232 signal 4.8K (optional 9.6K)
NMEA 0183: GGA, GSV, GSA, RMC, (optional VTG, GLL)
Coordinate datum: WGS 84
Power supply: 5 to 9VDC
Power consumption: typical (tracking): 120mW
Sleep mode power saving: yes (automatic)
RTC support: yes
Waterproof: yes
System performance: tracks up to 12 satellites L1, C/A code
Operating temperature: -40 to 85 degrees Celsius
Storage temperature: -55 to 100 degrees Celsius
Humidity: 5 to 95 percent