On The Run OTR.170 Hard To Buff, complete with 15mm broad pump action nib for wide lines. This is the smaller barrel version of the .070, truly pocket sized. Filled with classic Hard To Buff ink, this is one of the best and strongest alcohol based inks available. It's an incredibly hard to remove deep black ink that is glossy and highly opaque. This ink will mark most surfaces and, as the name suggests is highly permanent. A multi purpose marker for broad lines and filling in larger areas.