ESSO

Had an ESSO Gas pump (SPEEDPASS TRANSPONDER) RFID key tag. Opened it and found the alien-like transponder encased in glass. 

"QUOTED from Wikipedia": 

Speedpass was a keychain radio-frequency identification (RFID) device introduced in 1997 and was based on the Texas Instruments TIRIS RFID platform. Speedpass used a cryptographically-enabled tag with a Digital Signature Transponder (DST) which incorporated a weak, proprietary encryption scheme to perform a challenge-response protocol.

A group of students from Johns Hopkins University broke the proprietary encryption algorithm used by the Exxon-Mobil Speedpass. They were able to successfully copy a Speedpass and use the copied RFID tag to purchase gas.