Stay hydrated on the go with Ninja's Thirsti water bottle - get one for £4!

Staying hydrated and drinking more water is essential for maintaining good health. A good way to keep the habit is by carrying a water bottle with you on the go, and if you want the ultimate leak-proof solution, then look no further than the Ninja's Thirsti water bottle.

It's now available at its lowest ever price thanks to Ninja's latest sale - but there's a way to get it even cheaper. The Ninja Thirsti is suitable for both hot and cold beverages and comes in two sizes - 530ml and 700ml, available in a variety of stylish colours including classic white, grey, black, and vibrant blue and mint.

Normally priced at £29.99 for the smaller size and £34.99 for the larger one, Ninja has reduced them to £19.99 and £24.99 respectively, with free postage and packing included in their massive January sale.

But you can snap one up for even less, £3.99 to be exact, by signing up to the money-saving site TopCashback using the instructions below:

- Sign up to TopCashback for free here.

- While logged in, search for Ninja on TopCashback, click through and buy the item normally. Get £15 cashback when you spend £15 or more on an item - including the Ninja Thirsti, Ninja SipPerfect and anything else on the site.

- The cashback should track to your TopCashback 'Earnings page' within seven days of your purchase.