Accessories can improve the use of the dispenser and broaden the application range. So, from only using bottle-top dispenser for buffer medium, accessories such as a drying tube attached to the back of the bottle-top dispenser increase the performance for highly aggressive acids or bases. Therefore, the drying tube is filled with moisture absorber to avoid acid dilution by air humidity. Also bases can be protected from formation of carbonates when the drying tube is filled with the corresponding chemical. When preparing samples for HPLC a flexible discharge tube with a fine opening for dispensing liquid and a long reach into tubes is mounted to the bottle-top dispenser and simplifies dispensing of e.g., acetonitrile into small vials. Furthermore, also the general handling of bottle-top dispensers is explained in one video. Here you can see that de-airing of the device is mandatory to achieve accurate dispensing results.