28mm Toughened Double Glazing Unit - Size Range Width x Height (+ or - 100mm) (*we will call / email to confirm your exact mm measurements) 4mm Clear Toughened Glass - 20mm Silver Spacer - Argon Gas - 4mm Clear Toughened Glass Due to the bespoke nature of glass and the number of variations available - we are selling Toughened Double Glaze units within size ranges with a tolerance of + or - 100mm. We will call / email you to confirm the exact size in mm with you. Please note there is a 4mm seal around the side of the glass. Please see images.Key Features- 28mm Toughened Sealed Double Glazing Unit- 4mm Clear Toughened Glass - 20mm Silver Spacer - Argon Gas - 4mm Clear Toughened Glass- Argon Gas Filled- UK Manufactured- Free UK Delivery