Price: £16.67 GBP +VAT (£20.00)
The late type T25 / T3 / Vanagon low coolant level sensor used from around 1987 onwards in some, but not all models (251 919 372 A). This type has a clip on junior timer connector with a stainless steel spring clip which you squeeze to disconnect.
Either use for it’s intended purpose in a water cooled model, or just to fill the hole in the header tank if converting an air cooled model. You’re better off using the early version for the latter though, as they’re cheaper.