SRAM Apex 1 11-speed Rear Derailleur Long Cage 

SRAM's Apex® 1 drivetrain provides the gear range and the shifting simplicity to let you simply go where you want. The Apex 1 rear derailleur makes that gearing choice a reality with clean, crisp shifts, thanks to SRAM's X-HORIZON™ geometry and our ROLLER BEARING CLUTCH™. Just go: Apex 1 will get you there.
Features - Apex 1 Rear Derailleur
Long cage fits up to a 42 tooth cog
With CAGE LOCK™ technology, wheel removal and installation are easier than ever
Equipped with Roller Bearing Clutch™
X-HORIZON™ design reduces shift force, eliminates ghost shifting and chain slap
Large upper pulley offset automatically adjusts chain gap
Product Features
Use: Road, Cyclocross
Group: Apex 1
Cage: long
Mounting: Direct mounting
Gears: 11-speed
Compatible Chain: SRAM 11-speed chains
Compatibility: SRAM 11-speed Exact Actuation™ lever
Technologies: Cage Lock™, Exact Actuation™, Roller Bearing Clutch™, X-Horizon
Possible gearings: 11-42 T
Material
Outer cage: Aluminum
Inner cage: Steel
Color:black

Scope of delivery
1 x Apex 1 Rear Derailleur 11-speed Long Cage