I'am all for saftey,but how are these tethers any more safer than welded and bolted metal straps on each side of the collecter to the primary tubes?We use two straps and 4 tabs 1/2 inch wide with 1/4 inch bolts with stover style lock nuts.Cost of materials under $10.Header manufactures have been doing it this way for years.I would think that they should be acceptable.