Simonton. More windows in the StormBreaker Plus impact-resistant product line now feature Energy Tax Credit (ETC) glass packages. The glass packages are now available on picture and geometric windows, allowing them to meet U-factor and solar heat gain coefficient requirements for federal tax credit eligibility. The ETC Super Solar SBP glass package includes a 1-inch insulated glazing unit, Super Spacer system, argon gas fill, and low-E or LoE3-366 on the impact-resistant glass. ETC glass packages are also available on the maker’s replacement windows. 800.746.6686.