RM Ferrite Core Bobbins & Accessories Added 30 Nov 2020 Bobbins for RM ferrite cores in SMD or through-hole version, single or double-section are used mainly in wideband transformers, chokes, coils and resonant circuits. The advantage of these cores is a compact shape for optimal use of space winding with effective magnetic shielding. We hold in stock and available for immediate dispatch: - RM 4 RM 5 RM 6 RM 8 RM 10 RM 12 RM 14