Never lose your rule again helix ringbinder rule features a unique hole configuration that allows it to be used with the majority of ring bingers lever arch files and presentation ring binders this highly versatile shatterproof ruler is ideal for school children students and for home or office use ensure your ruler is kept safe and secure with this new innovation from helixpapprox dimensions 30cm 12 inchesprinted with cm mmcan be used with a majority of ring binders lever files an