This Diamond Guide has a stainless steel plate which gives it a heavier weight, increased longevity, a nicer glide & feel on the base. Highly sought after because you can file with your File Guide, set it down & then work with you Diamond Guide. This means there is no need to change the File for the Diamond Stone, therefore you save time & can dedicate your Diamond Guides for sharpening/polishing & use oil or water on them without the need to clean the File Guide each time you exchange the file for a stone. The Discs last longer then tradional rectangular Diamond Stones because you can easily spin the Disc, thereby using every bit of the Diamond surface. Diamond Discs NOT included, so please dont forget to order your Diamond Discs.