Item Id: 148
Item Data Value: 0
Weighted Pressure Plates emit a redstone signal when items are dropped on to it. The strength of the redstone signal is based on how many items are on top of it. Weighted Pressure Plate (Light)s require less items on it to emit the strongest redstone signal than the Weighted Pressure Plate (Heavy)s varient.
/give (user) (item id) (amount) (item data value)