Do you suffer from 80s video game nostalgia while also struggling with the metric system? Well, have I got the quick-print EDC tool for you!

Meet the five-piece Block Measurement Keychain Set capable of measuring from 10-40mm.

Each block segment measures 10mm (1cm) cubed, and each one contains 4 blocks in various configurations inspired by everyone's favorite classic 80s video game, Tetris.

It simultaneously acts as:

• a Ruler
• a Keychain
• a Calibration Cube

Simply print, then slide a standard keychain lanyard through the end slot. The curved inner surface within the slot ensures the lanyard can enter and exit easily. I have attached a GIF showing this process.

Lanyards used: https://amzn.to/4buAVF4

1" Keychain Rings: https://amzn.to/4boMpdl