Merck Fly killer Ectiban 25 is an emulsifiable concentrate premise insecticide formulated with 25% permethrin. It controls flies, stable flies, and lice when used as a surface spray in milking parlours, poultry houses, stables, and livestock housing. The liquid concentrate is diluted prior to use for fly control around cattle, poultry, and sheep housing. Supplied in a 473 ml bottle, it aligns with livestock health products used for premises.