GST classification of multiple-walled insulating glass units applies under the schedule and fixes tax treatment through a notification. Multiple-walled insulating units of glass are classified as taxable goods under the schedule and subject to GST at 18 percent until 21-09-2025; the entry was inserted by notification dated 14-11-2017 effective 15-11-2017, thereby placing the product within the schedule of taxable goods and fixing its GST treatment.