Sure, 0.5mm, which is the one that comes as standard on the RRP Mendel.
I've switched back to PLA after spending most of the year printing ABS so I found myself needing to sort out the cooling fan. So firstly I remixed a fan duct which works very well for me: [
www.thingiverse.com]
and then I I discovered that my hot end was ever so slightly tilted due to the slots on the nozzel mounting bracking having warped due to heat. So I moved my hot end onto a fresh slot (the RRP Mono can accommodate multiple hot ends) and it's made a huge difference to my PLA prints.
Cheers,
Rob