Discussed are a nitride semiconductor light emitting device in which a critical angle is increased by rounding corners of a substrate so as to improve light extraction efficiency due to increase in an amount of light generated from the inside thereof and extracted to the outside, and a method for manufacturing the same. Compounds of particular interest are defined by Formula I\u2032wherein X, A1, A2, A3, A4, R, R\u2033, R1 and R2 are as described in the specification. Medicinal products containing the a crystalline form of ivabradine hydrochloride, which are useful as bradycardics. Dowels are used to connect adjacent blocks. A control system is provided for pivoting the yokes including means for independently pivoting the yokes about parallel axes.