Hot Launch C523 irons combine maximum distance and forgiveness in a traditional cavity back design. The C523 Irons are made from extremely soft 431 stainless steel, providing superior feel and performance. The UST Mamiya HL-SST shafts feature Stabilized Shaft Tech, a softer tip and a mid-range flex. Stabilized Shaft Tech is an added cross weave that reduces ovaling for better stability during the loading and unloading of the shaft.