It is ANSI anti-picking grade 1, life time warranty. 10sec key change and so much more. The only down side is you need good skill to pick it if all keys are lost and/or changed as I can think of.
Well, if 3 or 4 doors each has different key, it is a true headache for both landlord and tenant, won't you think?
Techniquelly, traditional lock is super easy to rekey, just need to find the correct bullet set on ebay. The difficult part is to get the 鎖芯 out without lossing any parts. Usually deadbolt lock is much easier to reach inside than lock-on-handle type.
Watch youtube, changing a lock needs only 5 min for anyone who can bypass millions of peers in college entrance test, survive any American schools and has reached the point of landlord.
