The Truth Hardware (AmesburyTruth) 50 Series Encore Left-Hand Dyad Casement Window Operator (50.60) is designed for use in casement windows, pairing seamlessly with AmesburyTruth 14 Series Maxim Casement Window Hinges. Often referred to as a split-arm window crank, mechanism, or opener, the Truth 50.60 left-handed dyad operator is engineered to support window sashes weighing up to 55 lbs (24.9 kg), with widths ranging from 16" to 32" (406.4 mm - 813 mm) and heights up to 72" (1829 mm).

This operator is commonly identified with the stamp "31876" on the arm, though it may also feature alternative markings such as TH-24082, TH-24083, TH-24182, or TH-24183.