The Truth Hardware (AmesburyTruth) 99.20 limit device restricts how far a casement or awning window can open, so the sash can't swing out to a position where high winds can damage it. A short steel limit arm on a sill bracket slides in a 4-1/2" stainless steel track screwed to the sash, and stops the sash at the set opening. A detach clip disconnects it from the sash, so the window can be opened fully for cleaning or maintenance. Often called a window opening limiter, sash limiter, restrictor, or limit stop.

The amount of opening depends on where it's mounted. Truth's table for use with its concealed casement hinges gives mounting positions for 5°, 10°, 15° and 20° of opening with 10" and 13" hinges, and notes that the positions may differ with other hinges. Truth recommends a limit device or friction adjustor on any window more than two storeys up, and its concealed hinge sheet names a limit device as the alternative to a 90° stop hinge on casement windows with a Dyad operator. Mounting screws are included.

Specifications

• Part number: 99.20.00.201
• Type: Limit device with detach clip
• Opening: 5° to 20°, set by mounting position
• Track: Stainless steel, 4.500" (114.3 mm) long x .641" (16.3 mm) wide
• Limit arm: Coated steel, 5.453" (138.5 mm)
• Bracket: Coated steel, .625" (15.9 mm) wide
• Installed height: .438" (11.1 mm)
• Release: Detach clip (no key needed)
• Handing: Non-handed
• Screws included: 2 #7 x .750" Phillips pan-head steel sheet-metal screws (bracket) and 2 #7 x .750" Phillips pan-head stainless steel sheet-metal screws (track)
• Window types: Casement and awning