Off Center Fed (OCF) Antennas Combo Ring/Snap on/Slip on Packs - Mix 31, 61, 75 (.1-2000 MHz) Store/Ferrite Core Products/Combo Ring/Snap on/Slip on Packs - Mix 31, 61, 75 (.1-2000 MHz)Multi-mix, size or shape combination packsRing Combo PacksRing Combo PacksSnap-On Combo PacksSnap-On Combo PacksSlip On Beads Combo/Bulk PacksSlip On Beads Combo/Bulk Packs OCF antennas are very convenient as they will allow multiple bands of operation with a simple wire antenna which is fed off center with a 4:1 OCF Current balun with built in feed line choke,