The 2944666631 is a Wound Bead controlled for impedance limits only. Minimum impedance values are specified for the + marked frequencies. The minimum impedance is typically the listed impedance less 20%. Wire used for winding is oxygen free high conductivity copper with 100% matte tin plating over a nickel undercoating. If required the wound beads can be supplied with a tin/lead coating. The 44 material bead and wound bead is tested on the 4193A vector impedance meter.