18-20 Kaiyue special ★ plastic steel (non-metallic) 18-20 Kaiyue special ★★ thickened manganese steel 3D full encirclement 18-20 Kaiyue special ★★★ thickened aluminum magnesium alloy 3D full encirclement 18-20 Kaiyue special ★★★★ high-strength carbon steel 3D full encirclement 13-17 Kaiyue special ★ plastic steel (non-metallic) 13-17 Kaiyue special ★★ thickened manganese steel 3D full encirclement 13-17 Kaiyue special ★★★ thickened aluminum magnesium alloy 3D full encirclement 13-17 Kaiyue special ★★★★ High-strength carbon steel 3D full enveloping 06-12 Kaiyue special ★ plastic steel (non-metallic) 06-12 Kaiyue special ★★ thickened manganese steel 3D full enveloping 06-12 Kaiyue special ★★★ thickened aluminum magnesium alloy 3D full encirclement 06-12 Kaiyue special ★★★★ high-strength carbon steel 3D full encirclement