HYDRAULIC WELD ON THUMB Thumbs up! The AMI Hydraulic Weld On Thumb offers a practical option for operators who are looking for durability, impressive holding strength and flexible thumb positioning. Ideal for clamping and moving a variety of materials, including brush, boulders, logs and poles, the thumb folds tight to the stick when not in use and features serrated tines for better gripping. Available in multiple widths and lengths to match various coupler and bucket configurations..