Prepare For Launch The Competition Spec Hot Launch C521 Fairway is designed for the player seeking optimal launch and spin rates with minimal offset designs, while still enjoying the benefits of extreme ease of use and a high Moment of Inertia (MOI) properties that will tighten dispersion and increase overall accuracy.The Hot Launch 521 fairway metals are constructed of 17-4 stainless steel and features a thinner and lighter forged steel crown that increases clubhead speed for ultimate in power