(1) Set of New 80 grit, 1/2" hard tip for sizing close to TDC. I had these stoners custom made4 for when I was boring and honing blind hole Mercury outboard blocks. They are GY25 style. Range 2.5 to 3.3. For use with AN or HN style hones. I used them in 44ci blocks but can alswo be used for 22-66ci blocks.