Well worth the price for a quality lead refills for your mechanical pencil.
Just as advertised. Pencil leads are nearly unbreakable unless you intentionally break them: If you yield too much lead (click too much) on your mechanical pencil you run the risk of break off a piece, so only yield just enough for you to write with. Yes, the Pentel leads are as strong neccessary unlike some cheap disposable mechanical pencils. Just be careful not to press down too hard! Overall, you get what you pay for. Don't settle for cheaper leads!
Great way of storing eraser so head doesn't get dirty, Transport it it like a pen, in your shirt pocket, purse and/or pencil case. Replacement eraser can also be purchased.