Designed solely for use with Case-Mate's Leather Flip Case for Apple iPhone, the Signature iPhone Holster is sold separately for $25 or as part of a package with the Flip Case for an additional $15. Though the Leather Flip Case includes its own detachable belt clip, the Holster has a sturdier ratcheting version and uses a second layer of hard-reinforced leather to hold iPhone on your belt. It's your call as to whether doubling up on the leather is…