From the manufacturer

The Belay/Rappel Device or BRD is a versatile, lightweight device with engineered rope slots that give the belayer added control by increasing friction on the rope. It is single or double rope compatible for 8 to 11 mm ropes. The BRD has increased thermal mass and cooling fins to dissipate heat. It is anodized for longer wear. CNC machined from 6061 T-6 aluminum. Available with or without the Element locking carabiner.

Specifications

• Weight: 2.9 oz. (82 g)
• Meets UIAA standard for rope braking devices