To keep things simple, the new 2x12-speed Shimano ULTEGRA R8150 rear derailleur is now available in a single cage length. It's our fastest and most precise shifting system, and it's also affordable. The new 12-speed ULTEGRA R8150 rear derailleur shifts faster and more precisely than any other, and is more versatile thanks to a single cage length, compatible with cassettes with a 28-34T largest cog. Features:

Fastest rear shifting ever, 58% faster than the RD-R9150
Compact design with integrated wireless unit, charger and switch
LED status indicator
Battery level indicator
To link
Adjustment mode, etc.
Wider gear range
Max. largest sprocket: 34T

Specifications:

Model: RD-R8150
Series: ULTEGRA R8100 Series
Color: Group color
Average weight: 262 grams
Rear gears: 12
Top-Normal suspension type: SHIMANO SHADOW RD
Mounting: Direct mounting (conventional)
Max. difference/front: 16T
Capacity: 39T
Largest sprocket: Max. 34T
Largest sprocket: Min. 30T
Smallest sprocket: Max. 11T
Smallest cog: Min. 11T
Fluorine coated pivot bushings: 4
11-tooth derailleur pulley
Derailleur pulley with recessed type derailleur pulley screw
Di2 connection wired Di2 switching: Yes
Di2 connection wireless Di2 switching: Yes
Di2 Connection Wireless Bluetooth® LE Custom (*1)|Adjustment Mode Information: Yes
Di2 Wireless Bluetooth® LE Custom (*1)|Di2 Battery Level: Yes
Di2 Connection Wireless Bluetooth® LE Custom (*1)|Gear Position: Yes
Di2 Connection Wireless Bluetooth® LE Custom (*1)|SHIMANO STEPS Data Items (*3): Yes
Di2 Connection Wireless Bluetooth® LE Custom (*1)|E-TUBE RIDE Compatible: Yes
Di2 Connection Wireless Bluetooth® LE Customized (*1)|E-TUBE PROJECT Compatible: Yes
Di2 connection wireless ANT private (*2) Tuning mode information: Yes
Di2 connection wireless ANT private (*2) Di2 battery level: Yes
Di2 connection wireless ANT private (*2) Gear position: Yes
Di2 connection wireless ANT private (*2) SHIMANO STEPS data items (*3): Yes
Firmware update via E-TUBE PROJECT: Yes
SD50 Port (pcs): 0
SD300 Port (pcs): 1
SD50 connector (pcs): 0
SD300 connector (pcs): 0
System status LED: Yes
Charging port (pcs): 1
Charging cable: EW-EC300