The Mainstays 5" White Jacquard Smart Box Spring sets up in seconds and is available in Twin, Twin XL, Full, Queen, King, and California King sizes to create the perfect sleeping platform in any bedroom. Additional Information. The Mainstays 7" White Jacquard Smart Box Spring sets up in seconds with no tools required and is available in Twin, Twin XL, Full, Queen, King, and California King sizes to create the perfect sleeping platform in any bedroom. Account & Lists Account Returns & Orders. Set yourself up for a great night's sleep with the Mainstays 9" White Jacquard Smart Box Spring. Try. Product information Size:Twin. ASIN B084WRJ27N Customer Reviews: 4.6 out of 5 stars 79 ratings. The Mainstays 9" White Jacquard Smart Box Spring sets up in seconds with no tools required and is available in Twin, Twin XL, Full, Queen, King, and California King sizes to create the perfect sleeping platform in any bedroom. Product information Size:Queen: 79.00 x 59.50 x 5.00 Inches. This innovative box spring is designed to easily fold up for convenient storage and transport when not in use. Home & Kitchen Hello, Sign in. ASIN B084WGQDV1 Customer Reviews : 3.5 out of 5 stars 3 ratings. The Mainstays 9" White Jacquard Smart Box Spring sets up in seconds with no tools required and is available in Twin, Twin XL, Full, Queen, King, and California King sizes to create the perfect sleeping platform in any bedroom. Product information Size:Twin. Skip to main content.ca. The Mainstays 9" White Jacquard Smart Box Spring sets up in seconds and is available in Twin, Twin XL, Full, Queen, King, and California King sizes to create the perfect sleeping platform in any bedroom. Spring Mainstays 5" Easy Assembly Smart Box (Twin-XL): Amazon.ca: Home & Kitchen. Additional Information. Prime. The Mainstays 5" White Jacquard Smart Box Spring sets up in seconds and is available in Twin, Twin XL, Full, Queen, King, and California King sizes to create the perfect sleeping platform in any bedroom. Additional Information. ASIN B084WSHGY4 Customer Reviews : 4.4 out of 5 stars 11 ratings. The Mainstays 5" White Jacquard Smart Box Spring sets up in seconds with no tools required and is available in Twin, Twin XL, Full, Queen, King, and California King sizes to create the perfect sleeping platform in any bedroom.