High quality telescopic system to extend the measuring surface - the spirit level can be flexibly extended to the required length. Full length scribe edge - measure and mark in one operation, even when extended. Printed metric scale for determining internal dimensions and clear measurements. Lock system for fixing the set length - unintentional adjustment of the spirit level is prevented. Integrated slip stoppers ensure a tight fit when marking - no slipping of the spirit level. High-quality pull-out mechanism ensures high measuring accuracy - in normal position: closed ± 0.5 mm/m and extended ± 1.0 mm/m, in envelope position: closed ± 0.75 mm/m and extended ± 1.0 mm/m. Plastic end caps protect the profile in case of impact. Features: 1 horizontal level, 1 vertical level, 1 measuring surface, telescopic system, 1 continuous marking edge, 1 printed metric scale.