What's the difference between EpiPen and EpiPen Jr.?

The EpiPen contains a single dose of epinephrine (0.3 milligrams), which is appropriate for people who weigh more than 66 pounds. The EpiPen Jr. contains a smaller amount of epinephrine (0.15 milligrams). This reduced dose is appropriate for children who weigh 33 to 66 pounds.