stock losi flywheel. it only comes close to the tank if i shim it out enough to make the crank extender that i have work. the one i have measures 4.85 mm from end to end. i guess i can dremmel off a couple mm's. if i don't shim anything the crank extender is a good 2-3 mm too long. i tried using the stock losi nut that has a little extender and also a ofner version that has a little more extender built in, but the distance i need is right in between everything that i have.