Used on vari-drive MTD made LT's. This is the secondary belt or the belt going from the Transmission pulley to the variable drive pulley. Used on 600 series variable speed units. A 5/8 X 48" belt can also be used for this application however we recommend this belt made to OEM specs. This belt is a little wider than 5/8". A generic 5/8 X 48" belt is slightly different and costs only a little less than this belt. Use this belt for better results on vari-drive untis.