Limit Chain Tensioners are extruded then CNC-machined from 7075 aluminum for optimal strength and low weight. A minimalist design adds style while reducing their overall mass. A pair weighs just 62 grams/2.2 ounces. Limit Chain Tensioners are extruded then CNC-machined from 7075 aluminum for optimal strength and low weight. A minimalist design adds style while reducing their overall mass. A pair weighs just 62 grams/2.2 ounces. Laser-etched graphics that include wheel position guides and two 10-millimeter/3/8-inch mounting holes ensure perfect adjustability on most frames every time you remove and replace your wheel. When used properly, Limit tensioners will protect your frame dropouts and hold your rear wheel in place. Keep in mind, however, they aren't indestructible neither are your dropouts . Install these lightweight chain tensiners with care and leave the 15-inch breaker bar in your toolbox. CNC-machined from 7075 aluminum for optimal strength and low weight minimalist design adds style while reducing their overall mass pair weighs just 62 grams/2.2 ounces Laser-etched graphics that include wheel position guides two 10-millimeter/3/8-inch mounting holes Limit tensioners will protect your frame dropouts and hold your rear wheel in place