Bathtub plug

Update
My book released on ibook store now.
Please, check this link :
https://itunes.apple.com/us/book/very-easy-3d-modeling-workbook/id990807645?l=ko&ls=1&mt=11

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Hi everyone, thank you for watching and paying attention to my postings.
A few days ago, I had finished my brand new workbook and it is released on Amazon now.
It focuses on the beginner to intermediate, who want learn with the Autodesk 123D Design. It has over 2,000 pages and has a READER Friendly format. This book is helpful for your friends and even your kids.Also, the ibook edition is in review now. You may be able to see it in the ibook store soon. Thank you for your attention!
Please, check this link :
http://www.amazon.com/dp/B00XHT5QWI