Belkin 4-Socket SurgeMaster® with Telephone Protection (twin pack) is £12.16 @ Amazon.co.uk
Free delivery on all orders over £15, hence it is only worth to top up the order to this value. You may purchase a single unit for £7.98 inc delivery from ebuyer.com (see comments).
Description : The Home Series offers surge protection for your very basic household electronics and home appliances. This model offers 1034 Joules, 19,500 Maximum Spike Amperage, 4-outlets, Telephone/Modem/DSL protection and 2-metre power cord. This model comes with £50,000 Connected Equipment Warranty and our standard Lifetime Product Warranty.
Features : 1034 Joule energy rating provides standard protection for your basic electronic devices | Lifetime £50,000 Connected Equipment Warranty to insure protection for your connected equipment and give you peace of mind | 4 Surge-protected sockets | Telephone/modem/DSL protection | The Spoiler Cable System" for easy and clutter free cable management | BlockSpace" Sockets provide room for large, Acadapter blocks, without covering an unused socket | Safety Shutters help to protect users and their children | safety shutters over live and neutral ports | 2 metre power cable delivers optimal, safe AC power through a heavy-duty cable | Illuminated LEDs indicate your devices are ground and protected | Filters EMI/RFI noise up to 58 dB reduction | Maximum Spike Amperage of 45,000 Amps