metal 2 ring mechanism, metal 2 ring binder clip 2-ring mechanism: shape of ring: O/D/Q Length available: various from 87mm to 298mm Width available: various from 15mm to 36mm Inner diameter: various from 15mm to 78mm Color: nickel/silver Pull-open or with trigger. Features: 1) durable and environmental-friendly 2) can be easily attached and detached 3) rust resistant 4) high quality with competitive low price 5) can be customized