Function: the steel cores in the brake pipe from breaking the stop bolts under the strong tension during braking, affecting the normal braking function Package: Includes 100Pcs brake cable wire tip cap, 100pcs for 4mm derailleur / 100pcs for 5mm brake cable, optional : Black color, Lightweight, strong pressure resistance and Size: 4mm length: 18mm, suitable for variable speed lines tube with a diameter of 4mm; 5mm length: 17mm, suitable for brake lines with a diameter of 5mm Advantages:, will not hurt the cable housing, Manufacturer: ZBIianxer