SYNOVEX ONE Feedlot (trenbolone and estradiol extended release implant) is a growth promoting implant that is indicated for increased rate of weight gain and improved feed efficiency for up to 200 days in steers and heifers fed in confinement for slaughter. Each implant contains 200 mg of trenbolone acetate, 28 mg of estradiol benzoate and consists of 8 pellets.