Get the Lens of Truth and learn to crouch (1.8.4+)

This command will summon a little device, which will add a Lens of Truth and a bunch of new features, especially interesting for Minecraft mapmakers.

• Place 4 kinds of hidden blocks you can pass through
  
• Use the Lens of Truth to locate hidden entrances
  
• Use the crouch block to create 1 block high tunnels you can crouch through
  

Use it for your Adventuremap to give the players a Lens of Truth, so they can locate hidden entrances you set using the given spawn eggs. Create awesome puzzles and traps.

Important notes:

• The system won't work with a normal iron hoe.
  
• The main part of this concept is based on a project by samasaurus6
  
• Feel free to edit the commandblocks. 
  
• If you use this command as a Minecraft mapmaker, please name me somewhere in the map and leave a link to my YouTube channel!
  

Pastebin Link: Click here

Visit my YouTube Channel: Click here