This double steel ball bearing and 'Diff' spring piece is very versatile as you can wear it both horizonally or vertically.  You can also adjust the length as you can wind the leather strap around the spring itself to either fit as a choker or sit at chest level.  The lobster clasp is stainless steel.  A fabulous and easy wearable motor racing piece for anyone.
Measurements are:
Total length of the piece is 5.5 cm
Ball bearing width 1.5cm
Weight 55 grams