Jackson's : Alu Pro : Spanner

Alu-Pro Spanners Are Used Once The Canvas Has Been Attached To The Frame And Stretched. They Fulfil The Function Of A Canvas Key; That Is, They Are Used To Extend The Alu-Pro Frame At The Corners In Order To Tighten A Canvas Which Has Sagged Slightly. They Are Fastened With A Nut And Bolt Mechanism. Please Note, You Will Need A 4mm Allen Key To Use This Product. For More Information About Alu-Pro Products And A Series Of Assembly Tutorials, See The Alu-Pro Product Showcase On The Jackson's Blog. (https://www.jacksonsart.com/blog/2016/09/09/alu-pro-canvas-stretcher-bars-crossbars-tutorial/)