Synovex Primer Beef Implant : 100ds Farm & Home Start feeding SimpliFly® with LarvaStop™ Start feeding SimpliFly® with LarvaStop™ early in the spring before flies begin to appear and continue feeding throughout the summer and into the fall until cold weather restricts fly activity Features a locking pin to hold the outer tube in place Synovex Primer is a low dose combination implant with 50 mg of trenbolone acetate (TBA) and 7 mg of estradiol benzoate This implant is not approved for repeated implantation (reimplantation) with any other cattle ear implant in growing beef steers and heifers in a dry lot as safety and effectiveness have not been evaluated