Hondark 1ea 63X38X25mm Al 5.5uH toroidal Transformer core toroid ferrite core ferrite Ring core ferrite snap MnZn PC40

I purchased these for a high frequency application, < 30khz. Had to find out my own details, so for future shoppers:MnZn 40 is a soft ferrite core material with a number of characteristics, including:Material: Made from iron (Fe), manganese (Mn), and zinc (Zn)Properties: High permeability, saturation magnetization, resistivity, and permittivity, low power losses, and coercivityApplications: Power, shielding, and linear inductive componentsTemperature range: Can operate up to 200°CFrequency range: Generally used at frequencies less than 10 MHz