Milwaukee Electric Tools 2550-20 M12 Rivet Tool

Yeah, not cheap but definitely a case of buy once, cry once. I've been using it for about 8 months now and it's a great tool, does exactly what it says on the tin. Good build quality, very sturdy. It's nice that the spare nozzles are held on the tool so you can change them on the fly without coming down ladders etc but if you use a big battery you must remove the battery to change nozzles. I use it for stainless steel rivets between 3.2mm and 5mm diameter and lengths between 10mm and 30mm. It works great on all sizes, very fast and even on the largest rivets it takes them in it's stride. The spent rivet pin never jams which I really appreciate because it's one of my pet hates and it has a smallish pin collector on it that works well. On my installations I use around 40 rivets and it will do all those and more on a single small battery which is great not having to deal with the extra weight and bulk of large or multiple batteries. Very well engineered, well made and worth the premium price in my opinion.