R.E.K. 3000

The R.E.K. 3000 is a new item added into the 1.3 update of Terraria. It is crafted from a Tinkerer's Workshop combining the Tally Counter, the Lifeform Analyzer, and the Radar together. This item allows you to see your monster kill count, monsters around you and tells you if there is a rare monster near you.

Trivia
The name "R.E.K. 3000" could be referring to the phrase "REKT", commonly used when someone or something is killed. This is probable because of the accessory's monster-related effects.

R.E.K most likely stands for "Rares, Enemies, Kills", referencing the three functions of the device. The functions themselves are also listed in this order.