Bigsby B7 Specifications Model Name: B-7 Series: Original Kalamazoo Line Manufacturing Method: Cast Manufacturing Material: Aluminum Approximate weight: 354 grams/12.5 oz. Overall Length: 8 �" /222.3 mm Overall Width: 3 ?" /92.1 mm Arm adjusts with ?" Allen wrench and " socket wrench Bigsby B7 Includes: Tremolo Arm Assembly 6 Mounting Screws Spring Plastic Washer Installation Instructions