BiltBest Window Repair and Replacement Service Parts - Concealed Casement Keepers, Left-Handed and Right-Handed Service Parts Pack of Eight (8) Pieces (Four (4) of Each Handing). 

BiltBest was a long‑running window and door manufacturer known for its innovation in wood and aluminum‑clad products, windows and doors - operating for 66 Years before closing in 2010. Throughout the 1960s and into the 2000’s the company became an industry leader —developing one of the first aluminum‑cladding processes for wood windows and later adopting advanced insulating glass technologies. After more than 66 years in business, BiltBest closed its Ste. Genevieve, Missouri operations in 2010, though its legacy continues through suppliers like BiltBest Window Parts that still provide replacement parts.