PBO Makes Ultra Saber Fast Acting, Longer Lasting. Take Saber pour-on’s active ingredient — Lambdacyhalothrin— add a synergist, piperonyl butoxide (PBO), and you get ULTRA SABER — a powerful new force in controlling profit-robbing horn flies. PBO disarms hor flies’ ability to break down Lambdacyhalothrin, which increases the activity of the insecticide.This enhanced insecticidal activit of synergized Lambdacyhalothrin allows quick knockdown and extended duration of efficacy against horn flies. ULTRA SABER helps kil more horn flies faster and longer, to limit the stress they cause cattle and the associated economic losses they cause producers.Horn Flies Bleed Profits. Horn flies pierce cattle’s skin and suck blood up to 40 times per day.The results bleed producers’ profits, with millions of dollars lost annually.