Rennen Pentacle 110mm 5 bolt Chainrings are precision machined from aircraft quality 7075-T6 Aluminum ( 83% stronger than 6061) and available in Stealth Black. This is the first Integrated Chainring bolt nuts on the market. With a single speed specific tooth profile which have been designed to extend tooth life. At 2.29oz (65 grams, 42T) this makes Rennen 110mm Chainrings one of the lightest on the market. Rennen 110mm Chainrings are designed for younger riders 14yrs and younger at 150lbs or below.