YS YS-CFLX-N-2.85-1.0 COPPER FLEX Filament, Compatible with Ultimaker/Airwolf/Luzbot 3D printer, 2.85 mm 1kg, Natural Perfectly wound filament without tangles 2.85mm Filament Diameter (Tolerance: +/- 0.05mm) Quality Certificate: ROHS, ISO9001 Recommended Print Temperature: 190 - 240C Spool Diameter: 7.9" - Spool Width: 2.6" - Spool Inner Hub Diameter: 2.2"