Knockdown's key ingredient is glysophate which is a contact herbicide spray for general weed control. It is used to kill off lawns or weed or control infestations on areas prior to new lawns being sown. Note it must not be used on desirable grass or plants as it will damage or kill them. Available in a 1 litre concentrate bottle.
Tips for successful spraying: Ideally on a day where no rain is expected Spray old lawn and/or weeds at least one week before sowing.
If weeds are tenacious a second spray may be required.