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Surge protected or basic extension lead

Updated: 23 October 2026

You are choosing a lead for a television or a PC, and half the titles say surge protected. A surge protected extension lead is about short spikes in voltage. It is not extra amps, and it is not a lightning rod. Buy a stated joule rating for electronics you would be upset to lose. Buy a basic lead for lamps and phone chargers. This page is from the Products Compared editorial team. The joule figures below are what these amazon.co.uk listings print, checked on 21 October 2026, not a measurement we made. The full rows are in the [extension lead comparison](/hub/sockets-and-extension-leads/extension-lead). A qualifying Amazon purchase can earn us a commission at no extra cost to you.

You are choosing a lead for a television or a PC, and half the titles say surge protected. A surge protected extension lead is about short spikes in voltage. It is not extra amps, and it is not a lightning rod.

Our top picks

Masterplug Masterplug 4-way switched 2 m

Best overall

Masterplug Masterplug 4-way switched 2 m
9.6/10about £9.50
View offer
PARTH PARTH 6-way 5 m

Alternative

PARTH PARTH 6-way 5 m
9.4/10about £23.99
View offer
Desiretech Desiretech 4-gang 2 m

Best value

Desiretech Desiretech 4-gang 2 m
9.2/10about £6.99
View offer
On this page
  1. 1.Surge protection and the 13 A limit are different jobs
  2. 2.A basic lead is enough for lamps and chargers
  3. 3.A printed joule rating is the reason to pay more for a TV or PC
  4. 4.Surge protected without joules is a weaker claim
  5. 5.If the surge light is off, treat the protection as finished

Surge protection and the 13 A limit are different jobs

A 13 A lead can still be overrun by a kettle, surge chip or not. Electrical Safety First’s video says surge protection does not protect against overload. Overload is too much current for too long. A surge here means a brief over-voltage. Joules are the energy figure the seller prints for that job. They do not add amps. Masterplug’s SWSRG4xN family sheet states 370 joules and says the device is not a lightning arrester. The switched four-socket lead in this set is the one whose table says 370 joules. If you only needed sockets for a lamp, skip surge. The wider checks are on the extension lead buying guide.

A basic lead is enough for lamps and chargers

A lamp, a router and a phone charger do not justify a joule rating. The Desiretech 2 m, B08TWZD1H4, is £6.99 with no surge claim in the title. The Masterplug 5 m, B0001P0GDK, is £9.99 and the bullets cite BS 1363-2 rather than surge. Do not promote that 5 m lead because its table says 1 joule. The title says basic and unswitched, so 1 joule is not a feature. The Hanycony four-way at £15.99 claims overload protection and does not state joules. Overload wording is the breaker or the fuse, not a spike rating. A television you cannot replace is a reason to pay for a printed number.
Masterplug Masterplug 4-way switched 2 m

Testsieger

Masterplug Masterplug 4-way switched 2 m
9.6/10about £9.50
View offer

A printed joule rating is the reason to pay more for a TV or PC

When a television or a PC is why you are buying, choose a listing that prints joules, then compare length. Printed figures here are 370 J on the switched Masterplug at £9.50 and on the unswitched six-way at £10.82, 270 J on the DEWENWILS bullet, 1,050 J on the IECOPOWER, 1,700 J on the TESSAN and 1,800 J on the Hanycony eight-way. A higher number is not proof that 1,800 J is safer in your house than 370 J. We did not pulse-test these leads. The Hanycony lightning wording conflicts with Masterplug’s not a lightning arrester line. Do not conclude that this Hanycony stops lightning. For a desk within 2 m, the switched 370 J Masterplug is the straightforward step up. The short list is on the best extension lead page.

Surge protected without joules is a weaker claim

Both PARTH leads say surge protected and neither prints joules. The 5 m six-way, B09TFC1CG5, is £23.99 with individual switches. The 10 m six-way, B0CGHTNFS9, is £29.99. That can be the right lead when you have measured the run and you accept a surge word without an energy figure. It is a weaker claim than 270 J or 370 J, because you cannot compare an absent number. Do not fill the gap with a guess. The PARTH price is the switches and the metres, not a proven higher joule rating.

If the surge light is off, treat the protection as finished

Masterplug’s family sheet includes a surge indicator. The switched four-way and the unswitched six-way both advertise power and surge LEDs. If the surge light is off when the seller says it should be on, treat the protection as finished. Unplug the equipment you care about and replace the lead. A thermal cut-out is another limit, not extra capacity, and it does not make the lead a lightning arrester. The 13 A ceiling is unchanged.

Common questions

Do I need surge protection for a lamp and a phone charger?
No. A basic lead is enough for lamps, routers and chargers, provided you stay inside 13 A. The £6.99 Desiretech 2 m and the £9.99 Masterplug 5 m do not claim surge in the title, and that is acceptable for those loads. Pay for joules when the kit on the lead would be painful to replace.
What does 370 joules mean?
It is the energy figure Masterplug prints for the surge clamping on the SWSRG family, including the switched four-way and the unswitched six-way in this set. The family sheet also says the device is not a lightning arrester. Joules are not watts of extra load, and 370 J does not let you add a heater.
Why do the PARTH leads say surge and not give joules?
The 5 m and 10 m titles and bullets say surge protected and do not print a joule rating. That is a weaker claim than 270 J or 370 J. You can still buy them for switched sockets and a long cable. You cannot treat the missing number as if it were a high one.
Does surge protection let me plug in a heater?
No. Surge parts do not raise the 13 A limit. Electrical Safety First treats overload as a separate problem. A heater, a kettle or a toaster belongs on the wall socket, including when the lead has 1,800 joules printed on it. A resettable breaker is not a second chance to add that load.
What should I do if the surge light is off?
Treat the surge protection as finished and unplug the equipment you care about. Masterplug’s indicator exists so a failed protection circuit is visible. A bright light in a bedroom is annoying. A light that stays off is the warning. Replace the lead rather than hoping the television is still covered.

Related pages

How to use an extension lead

Extension lead

Best extension lead UK: who it fits and who should skip

Extension lead buying guide before you pick a brand

How long an extension lead should be for your room

Sources

Sources taken from the research digest. Prices and review counts are a stored amazon.co.uk snapshot, not a live check. This page did not run a lab test.

  1. SI 1994/1768 — Plugs and Sockets etc. (Safety) Regulations 1994 (retrieved 22.10.2026)
  2. GOV.UK — Electrical Equipment (Safety) Regulations 2016 (retrieved 22.10.2026)
  3. Electrical Safety First — Extension leads, cable reels and block adaptors (retrieved 22.10.2026)
  4. Electrical Safety First — Plugs and fuses (retrieved 22.10.2026)
  5. London Fire Brigade — Cables, fuses and leads (retrieved 22.10.2026)
  6. Scottish Fire and Rescue Service — Electrical safety (retrieved 22.10.2026)
  7. County Durham and Darlington Fire and Rescue Service — Extensions and leads (retrieved 22.10.2026)
  8. HSE — HSG107 Maintaining portable electrical equipment (retrieved 22.10.2026)