PKMN.NET :: Dex :: Power Weight
DEX -
ITEMS: Power Weight

In-game description: A Pokémon hold item that promotes HP gain on leveling, but reduces the Speed stat.
Price: 3000

Technical explanation and other notes
Multiplies HP EV gains by four, but halves speed when the item is held.

Fling: 70 base power. Side effect: No additional effect.