The Ever KFT R-07a Tücsöl (Cricket), open-frame single seat basic instruction glider appeared in 1938. The R-07a Tücsök was a reduced-scale Vöcsök to replace the Zögling.
The Ever KFT R-07b Vöcsök (Grebe) appeared in 1940, a productionized version of the R-05/R-06 Vöcsök.
The Rubik R-07d was a postwar Vöcsök with modified ailerons, 30 built 1955/56.
As a production series of the R-06, 361 were built. Rubik Aero Ever KFT R-07b Vöcsök Length : 20.669 ft / 6.3 m Wingspan : 38.058 ft / 11.6 m Wing area : 161.46 sq.ft / 15.0 sq.m Max take off weight : 430.0 lb / 195.0 kg Weight empty : 242.6 lb / 110.0 kg Max. weight carried : 187.4 lb / 85.0 kg Glide ratio : 15.0 Minimum sink rate : 177.17 ft/min / 0.9 m/s