Replacement belt for Thumler's Tumbler, applicable to any model A or model B series. Stock No. 401. During routine maintenance and bearing lubrication, ensure that oil is not overfilled to prevent it from dripping onto the belt, as this can lead to belt deterioration over time. Thumler's tumbler drive belt for Models B, A-R1, A-R2, A-R6 and A-R12 (heavy-duty thickness) Manufactured in the United States