ITEM NAME:Bike Chain Guide - Road Mountain Bicycle Single Speed Chainring Protector, with Description: Suit for narrow-wide 30-40T chainring (round chainring), 30-38T chainring(oval chainring), Adjustable design. Support specification: BB mount/ISCG-05. High-strength material, wear and resistance to deformation. Simple, effective, adjustable, Super Light, durable & great value. Designed for single ring set-ups to keep your chain in place and avoid it dropping off. They are simple to install. Specification: Material: 7075 aluminum alloy, Nylon Color: ISCG05 Black Color: ISCG05 Red Color: BB mount Black Color: BB mount Red Size Chart: Weight: ISCG05: 26g Weight: BB mount: 30g Length: ISCG05: 11.5cm / 4.53inch Length: BB mount: 10cm / 3.94inch Package Includes: ISCG05: 1 Piece of Chain Guide 2 Pieces of Screws 4 Pieces of Spacers BB mount: 1 Piece of Chain Guide 2 Pieces of Spacers SKU: FUZ0020115565007573.Suit for narrow-wide 30-40T chainring (round chainring), 30-38T chainring(oval chainring), Adjustable design. 1 Piece of Chain Guide. Color: BB mount Black. Color: BB mount Red. Weight: BB mount: 30g.