if youre meaning klonopins brand name for clonazepam, it is a potent long lasting benzodiazepine that is used for anxiety, panic attacks, seizures associated with epilepsy. it also eases opiate withdrawal and since its long lasting you dont need to take it as much. it is still very addictive because it is very potent 1mg is equal to about 20mgs of valium. it is in youre system for up over 50 hours. so realistically one time use will be in youre system for a little over 2 days for it to be undetected. the half-life, which is half of the drug out of yorue system is 18 to 50 hours.