So-called walking excavators are a speciality of European alpine countries. Thanks to their flexibly adjustable undercarriage, they are prefectly fit for working in mountainous regions an even on the steepest slopes.

The A91 is Menzi Muck's second largest excavator and resembled here in the “Mobil” version, which means only on driven pair of wheels. All A91 versions have in common the 140 hp engine. The Mobil version has an operating weight of about 10 metric tonnes (22,000 lb).

This model was published by FH Modellbau in a 1000 pieces limited edition and produced by ROS.