Gibraltar Flat-Base Cymbal Stand with Brake Tilter

Before ordering Gibraltar Hardware 8710 cymbal stand, I tried to get clarification of the stand's tube sections inside diameters. Gibraltar never responded, and 7 other retailers gave different dimensions to me. So, I ordered anyway. The inside diameter of the middle pipe section is 1/2". The inside diameter of the lower (base) section is 5/8". Guitar Center has the right numbers but doesn't make clear what they are measurements of - inside diameter, outside diameter, upper pipe, middle pipe, lower pipe, other? I wanted the inside diameter of the middle section of pipe in order to plan for my building a mounting piece for a cylindrical percussion trigger. This mounting piece would fit inside the middle section of pipe. Stand is sturdy enough, and I've built the mounting piece which fits well into the middle pipe section.