WJX Cartridge Needles is patent design make the needles run extremely stable and smooth, have the Lowest Tin solder to avoid chemical process to ensure safety. Special Rebound - there is four special elastics that lighten the pressure the needles bar Medical Grade LG PC - made by PC polycarbonate, Polycarbonate is colorless, transparent, heat resistant,impact resistant. Original Design - WJX patent cartridges design achieve better hitting skins performance Mix Size:1205RL、1207RL、 1005RL、 1009RL、 1007M、 1009RM、 1011RM、 1207HRL、 1213RM-1、 1215RM-2 each 2pcs