As the carrier particle of the weak nuclear force, he's downright obese. Not just heavy, he's also two-faced. He's priced a little higher but it's like getting two particles in one. W Boson is also part of the Boson 5-pack.
Approximately 18 oz/500 grams; 5 inches/12 cm across.
For ages 5 and up as it contains glued-on/small parts.