SKC61.9 Electrohydraulic actuator, AC 24 V, DC 0...10 V, 2000 N without spring return, 40 mm stroke. 
Key data to replacement product: Electrohydraulic actuator SKC60, AC 24 V, DC 0...10 V, 2800 N, 40 mm, similar functionality plus enhanced performance. 
Info: Operation with frost protection monitor QAF21.. or QAF61.. or remote setting unit FZA21.. requires SKC62UA (with spring return).