This 80ml catalyst dispenser holds 1000ml and will dispense between 10-80ml of catalyst. The catalyst is released by squeezing the bottle gently. This allows the catalyst to flow into the engraved output chamber on the top. Stop squeezing when the required amount is reached. The catalyst will remain in the output chamber.  Simply pour from the chamber into the resin and stir.
(If you need more than 80ml of catalyst, e.g. 120mls, pour in the 80mls first, refill the dispenser to 40mls, add to the resin and stir)