I bought a lens early this year thru Amazon ( though sold by someone ). I then apply for a Int'l warranty and got it in mail in a week or 2. Painless and a joy knowing you saves money.
Here is the confirmation email and procedures:
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Thank you for contacting PENTAX.
To apply for International Warranty please provide the following information:
* Dated proof of purchase, which includes your name, address, and phone number
* Model name
* 7-digit Serial Number from the lens
You may FAX this information to: Joe Virgil at: 303-728-0145
You may also mail this information to him at:
PENTAX RICOH IMAGING AMERICAS
633 17th Street
Suite 2600
Denver, CO 80202
Attn: Joe Virgil
or e-mail (with attachment) to:
joe.virgil@prac.pentax.com
However, International Warranty applies to the first year of ownership, only, and may not be extended or renewed.
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Singapore used to be the place to buy, now , I am not too sure.