Here's what other sites are saying:
Get 3 points of contact and excellent camming action with the tough Z shaped Onda Piton from Grivel. Provides plenty of holding power and it's good for stacking too.
- Mountain Gear
Description of Grivel Onda 50mm Thick PitonAn elastic and strong 'Z' shape piton. Three points of contact camming action under a load offer greater holding power. Good for stacking too.Features:2" length5/8" thick
- US Outdoor Store
Grivel Onda 50 Thick Piton (Fall 2007) The Onda 50 Thick Piton by Grivel are Z-shaped to provide three points of contact and an excellent camming action under load. These have incredible holding power and are good for stacking with normal angle-shaped pitons. Thin Ondas may replace the thicker Top (LA) style pitons, they weigh less and have better holding power although they can destroy the rock more during removal. The length of the piton is marked (in centimeters) near the eye so if you encounter one that's fixed you can tell something about it. Still, nothing beats a in.hammer test,in. which hopefully delivers a satisfying ringing sound. Specifications: Weight: 98 gm Size: 50 x 16.5 mm Materials: ChroMoly Steel Construction: Stamped Z-Shaped Piton