HYDRAULIC PIN GRAB COUPLER Connecting ease-of-use with jobsite safety is the AMI Hydraulic Pin Grab Coupler for Compact Excavators with five integrated safety features. From inside the cab, the operator can switch attachments quickly, easily and most importantly know it's locked on tightly. Protecting the operator from unexpectedly bumping the wrong switch in the cab is the upgraded two-stage control. The in-cab control features two buttons: the first requires the operator to press and hold for two seconds and then press the second button at the same time to reverse the hydraulic flow in order to release the attachment.