Review on Uning Detachable Keychains: Your Ultimate Accessory for Convenient Key Management by Jack Watkins

Some initial concerns about the security of the attachment turned out to be unfounded. These stick together well. I had to drill holes to fit the large keyring, 1/64" from 1/8" to 9/64" but without significantly losing the integrity of the keychain. I would have them again in a heartbeat.. Highly recommended.