For years, I have been keeping my car key and house key on separate chains or apart. My theory is that I never need them at the same time and I hate the bulk. The only time I carry them together is to the house or out the door to my car. This Key chain makes me less abnormal in this regard.

If I want to go running near home, I take just the house key.
If I want to drive to a trail to run, I take both and leave the house key in the car and keep my car key on me.
When I go to work, I take both keys but leave the house key in the car.

The Key chain is very simple to use, slide the ring off (preferably at the thinnest part). I hope it will be durable and last many years. I gave one to my wife who has never really had a decent key chain.