A patented wedge-lock system securely attaches the mirror without risk of damage to your vehicle’s stock mirrors. Simply slide the CIPA Custom Towing Mirror over your stock vehicle mirror, insert the wedge and tighten the knob. Extends 4.5″ to 5.5″ (depending on model) beyond your vehicle’s stock mirrors to provide unsurpassed rearview vision for greater towing safety. Fully adjustable mirror face is made using first-surface mirror technology, which features a protective glass surface in front of the reflective coating to increase resistance to scratches, image distortion and adverse weather conditions. Each model is molded to conform exactly to the contours of your vehicle’s stock mirror. Models are available for over 3,000 vehicle applications, and are available as a pair or individually. Designed and assembled in the USA. These Mirrors fit ONLY Chevy Silverado or GMC Sierra pickups for 2014-2018. Not designed to fit Tahoe, Suburban, Denali, Yukon, Escalade, Traverse, Colorado, Canyon or other GM models.