Features 1、Adopt high quality aluminum, excellently machined, finished smoothly 2、There are toothed or toothless 2GT timing pulleys in different sizes that you can choose 3、Comes total 5pcs belt pulleys in one bag which you may use for many projects 4、Perfect choice for building a 3D printer or similar projects 5、They are good replacement parts for old or broken 3D printer belt pulley Specification Features: Adopt high quality aluminum, excellently machined, finished smoothly. There are toothed or toothless 2GT timing pulleys in different sizes that you can choose. Comes total 5pcs belt pulleys in one bag which you may use for many projects. Perfect choice for building a 3D printer or similar projects. They are good replacement parts for old or broken 3D printer belt pulley. Specifications: Material: Aluminum Model: 2GT(GT2) Tooth Pitch: 2mm Type(Optional): Belt Width Bore Size Tooth 6mm 3mm 16T,Toothless 6mm 3mm 16T,Toothed 6mm 3mm 20T,Toothless 6mm 3mm 20T,Toothed 6mm 5mm 20T,Toothless 10mm 5mm 20T,Toothed Quantity: 5pcs Package Includes: 5 x Pulleys Package List