I've been using this style of keychain for nearly 20 years. I think the one I'm currently using is about 12 years old. I've never had a problem with any of them due to defective materials or poor craftsmanship.
They're extremely durable and makes changing keys out a breeze. I recommend putting your personal house and other miscellaneous keys on the end with the push button and leaving the female coupler for the car keys. If you have multiple vehicles in your family as we do, swapping out car keys only takes seconds.
I also recommend that in the unfortunate event someone where to demand you hand over your car keys, you can instantly detach ONLY the car keys so they have no easy access into your home should they dig through the car for personal information and find your address.
This is the only keychain I like, this is the only one I will ever use. It's not super sexy, it's not colorful -- but it's very dependable.
Prices vary where ever you go -- but for $2.00 it's not a bad deal whatsoever.
Pros: Durable, Sturdy, Easy to Install, Easy to Move, Good Size & Weight, Nice Design