The size, shape, minimum weight, and centre of gravity of the javelin are all defined by IAAF rules. The javelin must be held at its grip and thrown overhand, over the athletes shoulder or upper arm. This Javelin by Amber is an IAAF Certified Javelin and meets all professional standards and specifications. The tips are chromed metal, and feature a unique cord-wrap grip. Some of the best throwers in the world assisted in helping us produce this javelin. These competition javelins are constructed from a composite metal alloy.