The Terratrip GPS Antenna is a highly sensitive antenna that will give you the best possible signal to your Terratrip tripmeter. If you are in a stage where there are trees or high buildings, this antenna will continue to send a high strength signal to your tripmeter.The antenna has a strong magnetic base so you can just stick it on your roof without having to drill any holesCan be used as a spare to replace a damaged or broken antennaPlease note: The GPS antenna is only suitable for use with Version 4 (V4) Tripmeters such as the Terratrip 202 Plus V4 or Terratrip 303 Plus V4.