From Combine OverWiki, the original Half-Life wiki and Portal wiki
- The transponder allows the crate to be easily found with the radar installed in the Muscle Car.
- At the start of the Episode Two chapter Under the Radar, the Muscle Car is equipped with a radar in a Resistance outpost located near the Combine Autogun in the Outlands. It is aimed at helping Gordon and Alyx find Resistance supplies equipped with transponders along the road. Thanks to the device, each supply crate appears on the radar screen as a Lambda logo.
|Half-Life 2: Episode Two|
|Cache Checker (10G)|
|Find every radar cache in chapter Under The Radar.|