Integra Premier master slides for corded tracks. This item forms one part of the overlap set, the other part is the overlap arm.
Although primarily used on the corded Integra Premier curtain tracks; you could use these master slides in conjunction with the Integra Premier overlap arm to form an overlap set on Integra Premier hand drawn tracks.
The Integra range of curtain tracks including the Integra Premier were sold by DIY stores like Home Base under their own brand.
NOTE sold in quantities of 1 pair, photo for illustration.