The MUON-NEUTRINO is a sneaky, elusive little guy who is a bit more massive than the electron-neutrino. Like his svelte brother, he too prefers to remain undetected. He is also part of the Lepton 6-pack.
Approximately 2 oz (57 gm); 5 inches (12 cm) across.
For ages 5 and up as it contains glued-on/small parts.