RIFFE Spearshafts are made with spring stainless steel, heat treated to increase hardness and prevent bending. The original RIFFE-designed shark-fin tabs have a smooth finish capable of holding 1 or 2 power bands per tab. 5/16″ (8mm) diameter – 3 3/16″(8.1cm) barb.Size Chart28" - Competitor 0034" - Competitor 044" - Competitor 150" - Competitor 257" - Competitor 365" - Competitor 472" - Metal Tech 5