Large Format Interchangeable Cores, LFIC Medeco® Large Format Interchangeable Core cylinders are designed so that cores can quickly and easily be changed by non-technical personnel by using a special control key. The Medeco® Large Format Interchangeable Core cylinders are available in a variety of different sizes, formats and security levels. Cores are available to fit into rim and mortise cylinders, key-in-knob locks, padlocks and bored auxiliary deadlatches and deadbolts. M³ LFIC M³ & X4 CLIQ LFIC Classic CLIQ LFIC XT SARGENT LFIC XT Corbin Russwin LFIC Dealer Locator Enter Postal Code Advanced Search For Export Security Solutions, Click Here. Click here for Engineered Security Solution dealers.