The Barrier Sprocket is BSD's latest plastic guard sprocket style, built for grinding, sliding and everything in between. It's built from fully CNC machined 7075 alloy that's strong, durable and lightweight paired with a high density nylon guard that adds protection to your cranks and your chain. The BSD Barrier Sprocket can be run on 19mm, 22mm and 24mm spindles with the included adapters. ###section### Product Specs TYPE: Bolt-On MATERIAL: Alloy WEIGHT: 149.7g (5.28oz) Size: 25t, 28t