Preface: This is the first edition of CSA M500-1, Agricultural tractors — Rear-mounted power take-off types 1, 2, 3 and 4 — Part 1: General specifications, safety requirements, dimensions for master shield and clearance zone, which is an adoption, with Canadian deviations, of the identically titled ISO (International Organization for Standardization) Standard 500-1 (second edition, 2014-04-01). This Standard was adopted by CSA Group with funding support provided by the Canadian Agricultural Safety Association (CASA). CSA Group and the funding body disclaims any liability in connection with the use of the information contained therein. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. Scope: This part of ISO 500 gives general specifications, including speeds, safety requirements, the dimensions for master shield, and clearance zones for rear-mounted power take-offs (PTOs) of types 1, 2, 3, and 4 on agricultural tractors with a track setting of more than 1 150 mm (those with track setting width of 1 150 mm or less are covered in ISO 500-2).