This kit uses a low-permeability nickel zinc NXO-100 high-frequency magnetic, high-quality wire, waterproof box package, stainless steel bolts, Q9 . Our programs, providing high-quality package material and detailed description of the production, the complete elimination of the timidity of the primary radio enthusiasts, lovers can not only master the principle of Barron, but also produced a good performance of the device, to fully enjoy the of DIY . Small, field gantry can be fixed, portable, waterproof. NOTICE: It is DIY KITS not a finished product. This item's shell no punch holes. Because there are three types of antenna position, M are the same, different terminal punch locations. need according to their own choice of programs to choose punch antenna location. Circular models: NXO-100 Circular material: nickel zinc ferrite Magnetic conductivity: 100 Overall dimensions: outer diameter 31 mm x height 7 mm x diameter 18 mm Center frequency: 15 MHZ Application frequency: 1-30 MHZ Waterproof Case Size: 65mm x 60mm x 35mm Types of antennas: 1: 1, 1: 4, 1: 9 three production program antenna optional, 1: 1 and 1: 9 is three enameled hinge, 1: 4 is two enameled wire. 1: 9 balun suitable long-term antenna , with manual or automatic antenna tuner tune-day use. 1: 4 balun applicable LOOP antenna to antenna and Winton (200-400). 1: 1 balun antenna suitable for bipolar DP (inverted V n V), such as antenna (40-100). Kits include 1.5m wire, please fold to 3 fold, each fold 0.5m. 1: 1 winding : three-wire twisted around 7 laps, stranding extent (about 3-4 times per centimeter) 1: 4 Winding : two-wire twisted around 8 laps, stranding extent (about 3-4 times per centimeter) 1: 9 Winding : three-wire twisted around 10 laps, stranding extent (about 3-4 times per centimeter) Colour:As Shown Material:plastic Package Contents: 1 x Radio Balun Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.