Product Selection Guide STOREFRONTS - PRODUCT COMPARISON EFCO KAWNEER OLD CASTLE BUILDING ENVELOPE US ALUMINUM YES 60 FI Storefront System - Trifab® 601 - Series FF601 YES 60 TU Thermally Broken Storefront System 406 (T) Trifab® 601T Series 6000 Series FT601 XTherm Series 406X (T) Trifab® 601UT Series 6000 XT - YKK AP PRODUCT YES 60 XT High Performance Storefront System Featuring Dual Thermal Barriers Page-10 PS-1000-08 | Effective Date: April 28, 2020