The Loxx Pull It Up Fastener Upper Head Smooth XXL with Regular Washer is the two-part upper section of the Loxx Fastener System. This extra-long thread version is made to accommodate the thickest fabric assemblies that the regular washer upper heads can't handle. Included are both the button and the clinch nut to make a complete upper section (you will receive them screwed together). This button is compatible with any lower section stud for cloth-to-cloth and cloth-to-surface applications. Loxx fasteners secure automatically and lock tight until the button is pulled. This positive engagement is created by a stainless steel spring inside the upper head that fits around the ball head of the stud. The result is a fastener that won’t accidentally come undone but is still easy to operate.