I've been using this for quite some time in my Dudu, although not quite as good as this deal.
It's on 3 network, 25GB gets refreshed every month for a one-off payment of £35.56 plus delivery (no monthly charge/fee). The SIM data will be refreshed every month until May 2028, works out to around £1.30 per month.
Use code HUKDEXEC to get the reduced price at checkout.
The data SIM is technically for business use contracts (it's a bit of a loop hole to get the cheap plan). You just need to accept that you're a 'business' user lol. (there's no checks, VAT number requirement etc. There might be, or was when I did it, just a tick box to confirm it's for business use. No other checks are carried out. Have had a brief look at the site and couldn't see the checkbox anywhere now though)
I use it to stream my Tidal collection/use Waze on Dudu, plus general data connection if required. For most people 25GB is plenty
https://www.scancom.co.uk/collections/three-preloaded/products/three-25gb-pre-paid-per-month-data-sim-exp-08-05-2024?variant=55815211123063
