The design for this thing comes from tc_tea who published the print files on Thingiverse in May 2013 (Thing 84075). I have printed a number of these in firetruck red and in white as shown but they can be custom printed in any colour of course. (I have many of the colours available from Faberdashery)

The overall length is approximately 150mm, the rosebud itself being approximately 36mm tall. (They can be printed larger - the rosebud in the photograph with the blue background is around 60mm tall and has a total length including the stem of approximately 200mm. All of these things have been printed using PLA filament, the stems are in 'Greenery Green'.