Spy tools: What private investigators use to sleuth Covert surveillance requires extreme patience and the right gear. Joan Goodchild July 13, 2010 CSO Share Twitter Facebook LinkedIn Google Plus Here's a look at the products featured on PI Mall, an online resource for investigative professionals that offers items for gathering information without being detected. 1. Tiny audio recorder Photo credit: PI Mall According to PI Mall, this is the world's smallest high-grade audio recorder. Despite its size, it features high-quality sound and sensitivity for listening to conversations. 2. Mini camera Photo credit: PI Mall A high-resolution, mini camera stick. In addition to their use by investigators, Joe Seanor of PI Mall says devices like this are often purchased by people to spy on babysitters. 3. GPS tracker Photo credit: PI Mall The iTrail is the world's smallest GPS data logger. PI Mall advertises the device, saying "Simply place the small iTrail unit wherever you like; your car, child's backpack, virtually anywhere! 4. Micro bionic super ear Photo credit: PI Mall The bionic ear allows you to secretly hear from great distances. Its mini size, light weight and skin tone color allows for the wearer to hear from great distances without anyone even knowing you're wearing it. 5. Wire frame surveillance sunglasses Photo credit: PI Mall These glasses keep the glare out of the eyes but also contain mirrors on the inside corners so you can see behind you. 6. Pen recorder Photo credit: PI Mall This Pen recorder gives you the ability to audio record while you are taking notes, writing out a statement or record while the working pen is in your pocket.