Asymmetrical rim builds up with more balanced left/right spoke tension. Sleeved 6061 aluminum with 4.5mm spoke hole offset. Tubeless ready with strong tire retention bead . Offset: 25mm = 3mm, 30/35/40mm = 4.5mm. Rim tape and valves are not includedItem Specifications: Number of Holes, 32, Type, Tubeless, Size, 27.5", Manufacturer Spec ERD (mm), 554mm, Color, Gray, Model Name, AR 40 Offset, Material, Aluminum, Brake Type, Disc, Width, 40mm, Wheel Depth, 20mm, Weight, 585g,.