You are buying an original Sparklets Soda syphon spare or accessory.
Do you have a Sparklets soda syphon which is either slowly leaking from the spout or, alternatively, from the side of the head, where the control lever is mounted when you use the syphon? This is most likely caused by the age of the internal seals, which have perished or cracked in the 50 plus years since your Sparklets was marketed.
This listing is for a single item of a reconditioned nylon/plastic soda flow control plunger valve (although multiple items are available). These were originally fitted to Sparklets soda syphons in the period prior from - roughly - 1968 to 1982, (before which metal plunger valve assemblies were used). These fit most of the Sparklets range of soda syphons in this date range but may not properly fit earlier syphons. They were made of a white plastic - probably nylon - and have now been reconditioned by fitting them with a new/replacement tip end seal and side O ring seal. They are supplied in a plastic bag pre-lubricated with a food service approved silicone lubricant grease, and are ready to install by suitably competent people. Damage or breakage of this reconditioned part caused by improper installation by those not qualified or experienced to install this item is expressly excluded from any warranty or guarantee on serviceability or suitability.
See my other listings for period accessories.
P. S. If you happen to have a Sparklets soda syphon that you would like reconditioning, please see my other listings.