A hard bushing that is well suited for the larger engines and if you want the engine to sit really tight.
Fits all ASS motor mounts.

Now you can adapt your engine mounts to how you use the car.

Softer bushings for street and smaller/lighter engines and harder bushings for track/heavier engines.
Polyurethane has a longer life than rubber and is available in 3 different hardnesses, Shore A 70, 80 and 95.
Comparatively, the purple polyurethane bushing (Shore A 80 ) is a little harder than the standard ASS rubber bushing but provides less vibration and better service life.
See image with diagram to compare vibrations.

Assembly can be done by hand, but you need some kind of pressure to get the rubber bushing out.

A disadvantage of polyurethane is that it does not like heat, neither does rubber, but polyurethane melts if it gets too hot.
So keep in mind that the manifold/turbo must not be too close to the bushing, you may need to put a plate as a heat shield in some cases.

A set of bushings contains 2 complete bushings in 4 parts, 2 pcs stainless sleeves and assembly grease.
Keep in mind that some motor mounts have 4 bushings and therefore need 2 kits. For example. engine mounts for LS engines.