Zinc Plated Steel. Strong Three Arm Corner Design. Suitable For Flight Cases. Easy To FitSmall: Dimensions (Ball to Arm): 38mm Fixing Holes: 3.3mm Large: Dimensions (Ball to Arm): 77mm Fixing Holes: 5.2mm. Our zinc plated steel ball corners are a reliable way to protect your cabinets and flight cases from damage. These sturdy corners are easy to install- with simple surface mounting that requires no special tools or skills. Just use screws- rivets- or bolts to secure them in place and get the protection you need for your valuable equipment. Order your zinc plated steel ball corners today and take advantage of our fast shipping and excellent customer service. Choice of small or large.. flight case corner-ball corner