1. using CG quartz sand 2. bubble-free inner layer with coating 3. high thermal performance 4. customization available 1. using IOTA-CG grade high purity quartz sand(SIO2≥99.99%)2. coated inner layer with strict defect control(foreign inclusions, bubbles, bubble clusters, scratches/scuffs, structure faults, spikes, vapor clouds…)3. high thermal performance(strong heat resistance, high ...