R9 RD-R42 / RD-R42S (9/10 SP) - Rear derailleur. - Road bikes. - Model No.: RD-R42 or RD-R42S. - Cassette Compatibility: 10 / 9 Speed. - Cage Type: Long Cage (RD-R42) / Short Cage (RD-R42S). - Front Chain ring: Triple (RD-R42) / Double (RD-R42S). - Max. Sprocket: 28T. - Min. Sprocket: 11T. - Total Capacity: 39T (RD-R42) / 33T (RD-R42S). - Guide Pulley: Engineering Composite with Steel Bushing. - Tension Pulley: Engineering Composite with Steel Bushing. - Bracket Body: Aluminum / Black. - Bracket Pivot Seal: No. - Plate Body: Composite / Black. - Plate Pivot Seal: No. - Outer Link: High-Polished Aluminum. - Inner Link: Black Painted Steel. - Link Pin Bushing: No. - Outer Plate: Black Painted Steel. - Inner Plate: Black Painted Steel. - Weight: 288g (RD-R42) / 265g (RD-R42S). - Compatibility: Shimano 9/10 Speed Road Rear Derailleur Compatible.