The shimano tiagra rd 4601 10 speed rear derailleur offers professional level features and high performance aspects at an affordable price the shimano rear derailleur has a wide link design which increases the rigidity and the service life of the derailleur and it has an advanced light action for low friction shifting up or down the block shimano tiagra rd 4601 10 speed rear derailleur features alloy body39s and outer link leads to lower weight without compromising strength and durabilit