If you have a Yanmar engine with a yellow plastic dip stick, you already know that (a) they break, (b) they break often, and (c) if they break just right they can take your transmission with them.
This replacement is made of hard anodized aluminum. If your dip stick is 7 long, purchase the complete assembly.
If it is a different length, purchase only the cap. Take the hollow metal dipstick off our your existing assembly and attach it the aluminum replacement cap. (Just push the tube up into the cap and a plastic insert will pop out of the Yanmar cap, allowing the tube to be removed.)
The price of this replacement is about the same as two plastic parts from Yamaha. So in the long run, this is a more cost-effective way to go.