MFP Flameproof Power Metal Film Resistors Welwyn / TT Electronics MFP Flameproof Power Metal Film Resistors offer flameproof protection and a 0.1Ω to 1MΩ resistance range. Welwyn / TT Electronics MFP 1W or 2W resistors feature the smallest size package for their power rating. The series offers a 350V voltage rating and a -55°C to +155°C operating temperature range.