National Hardware's 1/2" x 3-15/16" Interlocking Spring Snap allows quick attachments of all types of material and equipment. Steel body and spring construction provide maximum durability. Designed to install and remove quickly and repeatedly. For quick repeated attachments in a wide variety of applications. For quick repeated attachments in a wide variety of applications. Medium Duty Rating with 360 lbs. Safe Working Load, always follow safe working load (SWL) limits included on packaging. National Hardware's Lifespan Limited Lifetime Warranty.