Jul 19, 2018 · Step1:Put Stopper onto vial. Step 2:Put flip off cap onto vial. Step 3:Take the crimper in your hand. Step 4:Put Crimper onto flip off cap. Step 5:Press the handle. Step 6:Check the effect,if the cap can slip,then check step 7. Step 7:If the cap is loose,just adjust the claw,then crimp the cap again.