Using a sliding ball-and-ramp, BallNutz protects small parallel-sided cracks better than any other piece of protection available. The head is so narrow and small they fit where the only other option for pro would be pounding a pin. Colour coded for fast identification. Lighter than a pin and far more easy to remove. Very good strength on loading considering such a small device. Certification: CE0120, EN: 12276 Made in Korea #1 Blue Weight: 31 g Strength: 7 kN Range: 3.7-6.4 mm #2 Red Weight:39 g Strength: 8 kN Range: 4.8-9 mm #3 Yellow Weight: 49 g Strength: 8 kN Range: 6.1-11.6 mm #4 Green Weight: 58 g Strength: 8 kN Range: 7.8-13.8 mm #5 Purple Weight: 73 g Strength:8 kN Range: 10.3-17.5 mm, Set (1-5)Weight: 31-73 g Strength: 8 kN Range: 3.7-17.5 mm