http://www.amazon.com/Kwikset-Cylinder-Deadbolt-featuring-SmartKey/dp/B004EPYSH8/ref=sr_1_5?ie=UTF8&qid=1390508974&sr=8-5&keywords=kwikset+smartkey
几秒换一个new key。If you lost original key(any kwikset smartkey) you can use
http://www.amazon.com/Kwikset-83260-SMT-RESET-CRADLE/dp/B00117DVY8/ref=sr_1_6?ie=UTF8&qid=1390508974&sr=8-6&keywords=kwikset+smartkey
to rekey it, you can search on youtube for the instruction.
可以到Ebay找旧的别人退的OPEN BOX OR MISSING KEY之类的自己再RE-KEY平均不到10块一把。姐姐说的那种额们用了不好用,可能有的同学会习惯吧。