PRESSITIN TUNA TIN CAN factory ,free sample,customized 100ml Pressitins is the perfect size for storing 3.5g of dried flower. To seal the tin you simply push the base plate (bottom of the tin) into the body of the can firmly until you feel it click into place. To open, you pull the ring pull and can reseal the can by using the plastic cap provided with the Pressitin.No tools needed for these Tins.