Thank you. I hope this answers your questions.
These engines are very low in vibration.
Roto is a product of Czech.(CZ)
The Roto motor is very high quality enginering product.
Check (CZ) engineering then there is no question that this is a top quality product. Roto Motor is the DA engines of Europe which RC enthusiast use in their quality planes. It is as good as a gas engine can get and once you take a look at it its literally a work of art. If you are wondering about Roto Motor you can google it and find some info here in the states and a few videos of it on you tube which you can see it runs amazing and sound better than a DA. Also CZ electronics are the best so the elec ignition is top quality as well, any one with experience using AXI engines knows the quality.