The main reason for Apple announcing a lower gross margin outlook for Q3 was the uncertainty behind the raw material supply chain issues prevailing during the last few quarters due to the Japan tragedy.

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They are working with the Not For Sale Campaign to source from that region specifically to benefit the producers and communities, bringing the material to a Cambodian manufacturer also committed to a fully transparent supply chain.

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This is accounted for by increasing raw material costs, currency movements (particularly the pound's fall against the euro), bottlenecks in the supply chain and construction in progressively more challenging sites.

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