I think the EGW is more heavy duty and isn't the part Sig uses. EGW has this to say about their extractor in their Product Details:
Due to popular demand, we were commissioned to manufacture a Sig Heavy Duty Extractor. The quality of steel used to produce Sig's original extractor is made with a low grade steel. If the owner of a Sig GSR fires an extensive amount of rounds, it is likely that the extractor will break. We machined our HD Extractor from tool steel for superior strength and durability. The pin and spring for this extractor are sold separately as a set to go with our extractor. It is recommended to change the pin and spring when changing the extractor. This extractor will work for ALL 1911 SIG models. We are unable to ship this part internationally.