Standard built-in keystone eliminator Heavy-duty casing withstands daily usage Rugged construction withstands the rigors of daily usage Adjustable locking ring provides ease for various height settings Complimentary 4-side black masking borders MaxWhite 1.1 Gain screen material is durable for every day applications and easy to clean 160 degree wide viewing angle for multi-purpose applications Available in black or white metal casings (most models) Optional fabric carrying case available