This economic heavy duty closer comes with an adjustable back-check, as well as offering an optional delay function. Applicable for interior and exterior doors from barrier-free size 1 to size 6, the C71N shares the same mounting-hole pattern as the popular Norton 8301/8501 models. Be it with the standard cover or our new slimline cover option, this aluminum alloy closer is reliable and aesthetically pleasing wherever it is installed.