Cloaking devices are stealth implements that allow the wearer or holder to appear completely invisible to anybody else. Although many renditions of these in fiction involve them bending lights and other emissions around itself to appear invisible, cloaks on Mobius just make the holder invisible with no explanation given.
The Hidden Zone is completely covered by a cloaking device, making it the perfect hideaway for people wanting to remain safe from Doctor Robotnik and rule over Mobius - if civilians could even find it. Robotnik wished to invade the Zone for years, knowing that the area held many treasures. He was finally able to locate the hideaway when Sonic the Hedgehog fell from the Sky Fortress right into the Hidden Zone, which Robotnik was able to track and destroy. No longer safe, the inhabitants fled to the Emerald Hill Zone. A similarly-named story showed a Badnik created by Grimer that used a cloaking device to make itself invisible. After causing a lot of damage to the Tropical Jungle Zone, it was revealed by Sonic who coated the wearer in wet leaves before damaging the system itself.
During one of her early solo adventures, Amy Rose was gifted a spinning Top by Tekno the Canary, but was captured mid-flight by an Eggrobo hidden behind a cloaking device.