Ferronics Inc ferrite choke type Z-Max 54-100-1 that specifically engineered for maximum impedance to suppress high frequency noise or oscillations. The 54-100 "Blue" is rated minimum impedance of 140 Ohm @ 10Mhz and a rated current of 3Amps. Minimum impedance over the range of 2 to 40MHz is 100 Ohm. Size 0.30" x 0.35" tall x 0.185" thick. Sold in a package of 4.