does anyone know were to get one online and how much they are? thanks

no its a plastic cover you put around your ball 2 draw a straight line on it. thanks anyway

Before you buy a plastic one, some of the cardboard tubes that toilet rolls are on are just about the size of a golf ball and can be used to draw the line.

You should be able to 1 from any golf store or club shop mate,complete with marker pen..

They have got them in my local Asda at the moment along with a putting mat and a few other golf bits

Picked one up from my local ASDA, about 2 quid, maybe less. I think it's helped me.

I've seen those ball markers, but the slot is pretty wide on them and you'll end up with a fat stripe rather than a fine line, I like rjusa's idea better, and cost effective.