Installing crown moulding is one of the best ways to add instant value to your home.The Kreg Crown-ProTM simplifies the most frustrating steps of the process so you make fewer mistakes and get the job done faster! This uniquely designed tool holds your trim at the exact angle required, eliminating the need for advanced compound mitre cuts and difficult 'coping'.It's unique curved design lets you compensate for a wide variety of crown moulding spring angles, and it's extension arms let you work with crown up to 14cm wide.25cm saws will work with crown up to 8.9cm wide, depending on manufacturer.30cm saws will work with crown up to 14cm wide, depending on manufacturer.