Milky White Insulation Polyester Film is a slightly hazy film with excellent handling properties used especially for electrical insulation, transformer (EI-40), motor winding, other general-purpose applications & specially for EI-40 ferrite core bobbin.
Thickness: 5mil (0.127mm)±5%, Width: 17.8mm±0.2mm, Length: 75cm ±5mm, Color: Semi Transparent Milky White.

EI-40 Magnetic Ferrite Core For High Frequency Transformers, Choke Coils, Inductors etc.
Core shape: EI-40, Size: L=40mm (1.57'') W = 11.7mm (0.46'') H = 35.3mm (1.39"), Set : One E and One I Ferrites, with One Bobbin.