No. You only need one jar attachment. The attachment fits over the opening with a flat lid between the top of the jar and the attachment. Pull the attachment off after sealing. See the video. Large-mouth jar attachments are available online. I've never seen them in a brick-and-mortar store, but readers have reported sightings. Be sure you buy the large-mouth jar attachment if you have large-mouth jars. Otherwise, buy the small-mouth attachment.