Please fill out the form below for Optical Flat and get a quote for part number GG-O-635 by Federal Specifications with NSN 5210008826636 and FSC Name is 5210 measuring Tools Craftsmens, please include required quantity along with expected turn around time. Our knowledgeable account manager will reply you shortly. Also check for the related parts for part number GG-O-635. ASAP Aerospace distributes nose to tail NSN components, sub-assemblies, and assemblies for the aerospace and aviation industry.