An LFIC differs from an SFIC core in that between brands the size and shape of the core can vary, even if they share the same keyway. In these cases one would need to match the door hardware's LFIC housing to that lock's same brand.
What is a SFIC cylinder?
The Small Format Interchangeable Core (SFIC) cylinders come in the 7-pin Everest 29TM R keyway. They can be used on a mixed cylinder campus with the SL cylinder options that share the R keyway and enable an upgrade to Primus XP levels of security.
Are Schlage cores interchangeable?
Based on a plug diameter smaller than the standard 1⁄2", SFIC cores are completely interchangeable with Best, Falcon and other SFIC installations.