The Ametric 37x10x900 Li belt is a metric, European standard variable speed V-belt featuring a 37 mm top width, a 10 mm height, and a 900 mm inside length (Li)
Unlike classic fixed-ratio V-belts, this wide, thin profile allows the belt to ride up and down adjustable-pitch pulley sheaves safely, altering drive speeds on the fly without slipping or rolling over. 
Technical Specifications