The Metolius Ultralight Curve Nuts from Metolius Climbing are among the lightest climbing nuts we tested. They achieve this with a unique feature, attaching the cable directly to the nut and eliminating the swage, which results in less weight and bulk. Metolius Curve Nuts pop out less frequently from rope drag than other nuts. Their features may contribute to the fact that they are the most difficult nuts to clean. Metolius offers a decent size run but we wish they could make smaller sizes in aluminum; without them they fall one or two nuts short of a stand-alone rack.
The cables get kinked over time, but Curve Nut cables are more durable than those on other nuts that fare as well in the placement category: DMM Offset Nut and Wild Country Superlight Rocks. Curve Nuts are our top choice for parallel sided cracks. If you are just looking for a budget climbing nut, we would go with the Black Diamond Stopper or Cypher Huevo.