Barefoot International Boom Handle AttachmentBarefoot International Boom Handle Attachment The Barefoot International Boom Handle Attachment fits over the end of any B. I. boom and locks in place with a set screw. It adds 17. 5 inches of length and narrows to a 1. 25 inch diameter handle, making it easier for children and riders with smaller hands to grip the boom securely. Made from high quality aircraft grade materials to match the safety and reliability standard of all Barefoot International