This is a performance replacement part for the engine Pitch Mount on Subaru Impreza engines.
It is the Ingalls PowerStick and is a bolt-in part. Price for a new one is $100 - $140.
This one has the Rubber bushing as opposed to the Polyurethane bushing (too hard).
Installation Instructions included - takes about an hour.
Here's the official propaganda:
The PowerStick Pitch Mount is engineered to reduce deflection under hard acceleration and cornering for improved performance and power to weight transfer. Deflection in the motor mounts, as with the chassis and suspension, is a formidable enemy in power and weight transfer, robbing valuable horsepower and control.
The innovative dog-bone or pitch mount replacement eliminates the huge amounts of movement and torque shock that causes wheel-hop and vague power transfer. The PowerStick transfers more power to the road and improves acceleration, shifting, overall control and balance.