Instant Heat Therapy Pad, Large (p&p 99p Worldwide)

Very good. After a bit too much use they do occasionally get micro holes and need to be thrown away, but this happens with most heat packs (or at least any using a liquid based technology, including the oil/cotton filled 'hotties').Whilst the instructions specifically say not to, I microwave ours to recharge them with great success (3 minutes then give them a squidge, then 1.5 minutes to finish. If you hear boiling or crackling it is because there was a thin bit which is boiling faster than the rest... just turn them and give them a squidge to make the contents even and flat and continue with the above routine).I now have 5 of them in constant rotation since they are great when the wife gets a tummy ache in the middle of the night and I can simply grab one from the bedside draw and solve the problem.Update: after 4 years of regular use I've still got 3 out of 5 working. One I burst by over cooking it in the microwave, one got a tiny hole. I remain very happy with this level of durability and will buy more.

Quick to heat up. Long heat period. Ideal size and easy to restore back to Gel. Well pleased with it.