Thin section bearings are deep groove ball bearings. The type designations vary according to the manufacturer (e.g. 61800 for SKF and FAG = 6800 for NSK or 61900 for SKF and FAG = 6900 for NSK). The difference to a normal deep groove ball bearing is the ratio of the inner diameter to the outer diameter. The outer diameter is very small in relation to the inner diameter. In addition, the narrow design is ideal for installation where there is little space in the housing but a relatively large shaft must still be used. Due to the "light" design, thin groove bearings are also well suited for high speeds. Fröhlich & Dörken offers thin-section bearings in a wide variety of makes.