Replacing gas strut in a Selden Rodkicker - 2500N Edition

My old gas strut is bad so I need to change it to a new. The original is pretty expensive so i order a unoriginal from a Danish firm at www.fjedre.dk At seldén´s site it is mentioned you can get the gas strut in three different sizes for the Rodkicker 10 "normal (600N) - hard (1200N) - ekstra hard (2500N)" Maybe a fault from my site to buy a 2500N. but time will show if it is ok or not for my boat. The "2019" update : I have changed my 2500N strut to a 600N due to the 2500N was so strong it could carry my bodyweight (85kg) and the boom, the other problem was the 2500N was to hard for my ropes and the rodkicker connections. Think the 600N gives a nice balance between the rodkicker and the boom lift, so choose a 600N if you have a 32-40 feet boat.