The Pym Discs were created by Henry Pym using Pym Particles. They are used to shrink things from a distance.
Wolverine and the X-Men & Avengers: Earth's Mightiest Heroes! (Earth-8096)
The Pym Discs were created by Dr. Hank Pym. They are used to shrink the objects they are attached to using Pym Particles. However, the prototypes keep shrinking the objects until they become sub-atomic. When Ant-Man's Suit was stolen by Scott Lang, he attempted to use the Pym Discs to steal money, but was unsuccessful, only managing to shrink four stacks of money into nothingness. Later, Hank used a perfect Pym Disc to shrink Scott's daughter, Cassie, to the size of an ant to protect her from Cross.
Marvel Cinematic Universe (Earth-199999)
The Pym Discs are devices used in conjunction with Ant-Man's Suit, both created by Dr. Hank Pym. They are boomerang-like discs filled with Pym Particles. The devices can be thrown easily and are activated when they hit their target. The discs effects vary on the type of disc: Red discs shrinks the target, while blue discs enlarge the targets.