5Dev 8-Bolt Spider for 2x Dura Ace. Features: Allows the use of Dura Ace 2x chainrings with 5Dev 8-bolt cranks Chainring Bolt Pattern: Shimano 4 Bolt 110BCD for Dura Ace 2X Chainrings (will not work with Ultegra). Please note that this spider is cut to work exclusively with Dura Ace 2X Chainrings CNC machined in San Diego 73g Specs: Model: 8-Bolt Dura Ace Spider Configuration: 2x Direct Mount: 8-Bolt BCD: 4x110mm Color: black