612 ml per fork leg. More than usual on a lot of bikes but when I poured out the old oil I put it in a container and the filled a 500ml beaker and there was at least the remaining 112ml in the container. The Matris is a complete fork cartridge. You'll need to look at the inner lower fork legs (hard to see) which brand of forks you have in there. I also put in a blend of 5w Motorex that was included and Amsoil Shock Therapy 10w at 306ml per oil. I wanted the oil to be around 7.5w. In the Guzzi Eldo shop manual it recommends 40,000km on the fork oil. That seems like a lot of km's before change. Most bikes I have had wanted it replaced at 12,500-20,000 miles. Just like it says in the final drive that it can go 50,000km before change. All my previous Guzzi's suggested changing the final drive oil at 8-12,000 miles. Anyway, I changed all the oils as I had the bike apart. Won't have to worry about it for a while. One thing I have noticed is with the adjustability in the Matris you can get the forks much more compliant and not as heavy a compressed feel. In other words, a softer ride or you can make it as harsh as you want.