LC-P002 pressurized vacuum tube Solar Energy Project 1,high heating efficiency 2, easyly ... installation 3. energy-saves LC-P002 pressurized vacuum tube Solar Energy Project Specification:1) Vacuum tubes: Φ47 x 1 ... ,500mm, Φ58 x 1,800mm, Φ70 x 2,100mm2) Vacuum tube size: 15, 16, 18, 20, 24, 26, 28, 30, ... temperature preservation can last 72 hoursPacking:Standard export carton and foam