Some years ago I bought a store-branded soldering station (because it was cheap). I soon regretted my decision as the store only carried two kinds of spare tips: one conical and a huge chisel.
Recently the store stopped carrying the model and while they say that spare parts are available for at least 5 years, there will eventually be a time when I'm all outta tips.
So if you recognize the manufacturer or can recommend suitable tips based on the dimensions, that'd be awesome. I've tried a Hakko 900M tips and they're slightly too thin and fall off.
The spare tips: http://www.clasohlson.com/fi/Juotoskärjet-Cotech/40-8342
The tip dimensions: outer diameter 6.4 mm (upper end) to 6.7 mm (lower end), inner diameter 4.6 mm, hole depth 24 mm, and finally the outside length 26 mm.
The heating element diameter is 4.5 mm.