A canvas worker would call this a "Dot Common Sense turn fastener, single screw male". There are several different types of the male, fitting. One with single screw, one with two screws, one for canvas with prongs which bend over and one for canvas which has two buttons holding in pace on other canvas. .
The commonality is the female commonsense fastener:
In this case the Dot common sense male has two buttons for cloth. The female is typical for all of the male fasteners. Although one can cut the canvas for the female with a hot knife or specialized soldering iron, it is much easier to buy a specific common sense female punch.
Here is a photo of the punch I use for the female holes for the Dot Common Sense female fastener.
When I made a totally water proof camper back for the C Dory 25, I used many of the common sense fasteners, in this configuration thru the ShelterRite, vinyl material.
The latter part of this page shows all of the different Dot Common Sense combinations you can use.
