In the La Tene I, or La Tene A to B2, era (4th to 3rd centuries BC), fibula design became relatively standardised over a large geographic area, although minor stylistic variations and differences in decoration remained. The La Tene I fibula usually had a narrow bow. The spring that could be either unilateral or bilateral, was wound in a fairly large diameter circle. The foot was turned up and usually ended in a decorated knob or with an applied bead or stone. In some cases the raised foot was bent back towards the bow, although it did not touch the bow. The Thraco-Getic fibula is a variant found in the eastern Balkans and used by the Getae. The fibula's foot is vertical and ends in a small knob, though later models had a sinuous, s-shaped profile.