This thing is cheap, but I wanted cheap. Cheap is the best attribute.Assembly requires a 12mm hex or Allen key. Most sets end at 10mm so get one of you don’t have one. You also need outer ring clip pliers (and a spare ring clip because you’ll bend one)There are no assembly instructions other than a parts diagram on the single sheet “owners manual”. The pumping lever is difficult to install. You will need to compress the spring in a vice, zip tie it in compressed form, reinstall and the attach pumping lever.Comes with a spare set of piston o-rings… which might not be a good sign!