SINUS 912 & SINUS FLEX:
Sinus motorglider combines a true sense of a glider with unprecedented efficiency during powered and long-range cruise flight. With the Sinus you can take-off and land on very short runways, fly long distance cross-country and have fun gliding with a 27:1 gliding ratio… all in the same aircraft!

With the standard Sinus model, you literally purchase three aircraft for the price of one. You get a glider, a long range super-economic cruiser and the most versatile training aircraft on the market. Thanks to its dual flight controls and a choice of either tailwheel or nosewheel undercarriage the Sinus can be used as your primary gliding and powered-aircraft trainer! The excellent performance was confirmed with a World Champion title in 2001 and a record-breaking solo flight around the world in 2004. 

Three aircraft in one not enough? You can further enhance the Sinus with a very small addition – the Flex. Sinus Flex model is identical to the standard Sinus, with the added bonus of interchangeable wing-tips. The outer 5-foot portions of each wing can be easily taken away and replaced with short winglets of a Virus model.

You could not decide if you wanted a Pipistrel Sinus or a Pipistrel Virus? Now you can have both, transforming a thermal-soaring Sinus motorglider into a small and fast Virus cruiser, which can fit into any hangar. The change is is easy and only takes five minutes.

Original source:
https://www.pipistrel-aircraft.com/products/gliders/sinus/