Sinz expert chain Tensioners give you the same look and functions as the Pro Tensioners, but at a more affordable price. Made from a cold forged Aluminum (rather than CNC billet Ali), Twin holes give you all the reach you will need to keep these as far up on your dropouts to not only keep your rear wheel from moving, but also lengthen frame life by giving you a more secure clamping area on your dropouts. Sold as a pair