RGR Black Lanyard - 57cm - Black Whistle Cord
The whistle cord has one fixed and two or three sliding runners (one can be removed). The inside runner should hold the cord under the armpit and the remaining runners evenly spaced. Sgt and CSgt wear a whistle cord with three knots, WO2 and above wear four knots. It is worn on the left hand side and the clip fastened on the pocket.