This product is a re-manufactured neck-seal and dip-tube assembly intended to fit the following models of Sparklets soda syphons:  Hostmaster Mk. 1, 2 and 3 plus Aquarius and Globemaster.  The outer diameter of the neck seal is 32mm and its thickness is 7.5mm; the central hole is 7.7mm in diameter. It is supplied with a 20+cm long soft plastic dip-tube which can easily be cut to the correct length for your actual syphon.  
Price includes UK postage; non-UK buyers will need to inquire about postage costs to your country. 
Contact us by e-mail to purchase (PayPal, BACS, IBAN and WISE all accepted)