Today, for almost all products, the appearance is very important. Thus, for example, the appearance of universal gear reducers was not given so much attention, but today there are many very interesting solutions of shape, colour and graphic design. It should have in mind that universal gear reducers have much complex construction comparing them with special gear reducers. In the same time, they have to provide different positions and way of mounting and different speeds with different powers (torques) at the output shaft. Particularly, it should be noticed, that within all universal gear reducers single-stage gear units are nowadays increasingly used because their gear ratio values are increased (values of gear ratio can go up to 15) so that these reducers largely cover most of the two-stage gear reducers with their gear ratio values, so thereby their exploitation is significantly increased. Single-stage gear reducers are very simple products, and today there is a large number of manufacturers of such product. However, their mounting dimensions and way of mounting are not defined by a standard, so there is a variety of units with different dimensions and way of mounting. Although, most manufacturers look up to dimensions of leading manufacturers (usually SEW) in order to ensure greater exchangeability of their gear units. It is interesting to note, that most manufacturers tend to adopt the design of housing that will be substantially different from competing solutions. The reason is probably to avoid the possibility of being accused of copying someone else’s solution. However, there are manufacturers that retain almost identical housing design as a competing solution (probably they bought the licence or the solution is copied without permission). This paper considers only the design solutions of single-stage gear reducer in order to indicate the expected directions of their further development.