RV3 Series chains feature a 3 pocket sealing system with up to 10 times the wear life of standard o-ring chains. HFRA (Hyper Fast) 520 conversion kits with 1 down in front, 2 up in rear gearing with Hardcoat aluminum rear sprocket.. On the continent of North America. Photos are for reference only. Actual product may differ from the item shown in photograph.