The flaps are sold as pairs or full truck sets. If it is a full truck set the page will say so and show a picture of 4 flaps. All the options for this style can be found here, https://www.sharptruck.com/gatorback-gmc-logo-with-black-wrap-mud-flaps
The cut style flaps work best on the front wheel wells and do not require brackets. You can use factory existing screws in the lip of the fender or use the included self tapping screws to install