Competition & Training Hammer Conversion Circle. Reduces the discus circle diameter to 2135mm, 4 elements assembled together by means of single-head feather key. Steel Galvanised or Fibre Glass construction. Aluminium Hammer Cages, height 7 m, gate height 10 m. Independent aluminium pillars anodized in silver colour, certified net, easy to assemble and dismount, simple operation, high reliability. Pillars screwed to special anchors embedded in concrete.