Pot Cores Fair-Rite POT Core configuration provides a high degree of self-shielding and facilitates gaping to enhance utility for a variety of magnetic designs. POT Cores can be supplied with the center post gaped to mechanical specifications as well as an AL value. Fair-Rite POT Core is available in a range of sizes from P9/5S to P36/22 and 3 materials with Initial Permeability ranging from 2300 to 3000.