A folding rule has been the most used tool for over 50 years and this guide is a practical supplement to it you can use it on insulating boards wallpaper walls metal sheets plasterboards etc thumby will give you a safe guide undesirable wavy lines will belong to the past it belongs in every tool box or case also ideal for diy jobs around the house measure draw and save time no problem with thumby the practical aid for your trouser pocket no longer have curved lines whe