First Type

The Romanian Loyal (faithful) Service Medal was instituted in 1878 and was awarded for long or meritorious service to both civillians and to members of the military. It could also awarded to foreigners.

The Type 1 of the medal was awarded until 1932 and was awarded in two classes. The Class I was made in golden metal, and class II was made in silver metal.

Generally, the class I was awarded four years after the award of the class II medal.

The Loyal Service Cross was awarded for life, but could be revoked if the recipient was convicted of a crime, or was found to have done 'dishonorable' deeds.  The cross could also be awarded to foreigners.

The Ribbon is blue with silver edges.

Second Type

The Type 2 was awarded from 1932 to 1947. It was awarded in three classes. Class I was made in silver gilt, class II in silver, and class III in bronze. Starting in 1937, the type II medal could also be awarded with swords to denote a wartime award.

The ribbon is blue, flanked by 3 mm silver stripes.  During times of war, the war ribbon was substituted.  This included the addition of  3 mm gold stripes on the outer edges. 

The medallion is 33 mm in diameter. The obverse of the medallion displays two lions supporting the Romanian Royal coat of arms. The coat of arms is topped by a crown, and the bottom scroll reads: "NIHIL SINE DEO" (Translation: "Nothing without God")

The Obverse reads "Serviciu Credincios" (Translation: Loyal/Faithful Service), surrounded with a wreath of laurel and oak leaves.

Of special note is that the crown is of different construction than that of the first type (see pics), and the medal has a slightly larger diameter.

In all there were 8 variations of the medal.
 

References 

Littlejohn, David. Foreign Legions of the Third Reich. R. Vol 4. R. James Bender Publishing, p. 118.

Pankey, Charles. Original research.

Catone, Stefan; Serbanescu, Neculae; and Dumitrascu, Bedivan. Romania Decoratii 1859-1991; Realizat Prin Cover; 1992.