These EXtreme Bash (EXB) specification Shock Collars provide fast and consistent ride height adjustmentsFeatures:ARRMA EXtreme Bash (EXB) parts are made from extremely strong and durable materials and engineered to survive the most grueling action Constructed from aluminum material for added stiffness and strength - Precision CNC machined threads for smooth adjustments in all conditions - Tactile edge profile for easy spring preload adjustment - Anodized black for cool looks and increased durability - Includes O-rings to ensure consistent ride-height settingsIncludes:2 x EXB Aluminum CNC Shock Collar 2 x O-Ring