I bought this for my Lotus Excel, it was less than half the price of the Otter switch at the usual Lotus specialists. Fits in the hole perfectly, needs some sealant though, don’t just fit it with the rubber seal (included with the switch) dry! Head is a fair bit smaller than the original factory switch so the metal retaining clip achieves nothing, but wire tie or cable tie works fine to hold in place.
Quality seems fine, but in this weather the engine hasn’t yet got hot enough to see if it actually turns the fans on when needed!