While it sounds violent, it applies what's called "percussive therapy" – a popular technique used in sports rehab and by professional athletes. The gun allows athletes to recover faster and perform better, though it's equally effective if you need pain relief from spending long hours in front of the computer or from sitting in the same position. Other benefits include better sleep and improved flexibility.
Theragun offers three models which are all on offer: the budget Liv has £50 off (was £229, now £179), the mid-range G3 has £75 off (was £375, now £300), and the top-tier G3Pro has £135 off (was £549, now £414). You pay for more features with the higher end models, such as two speed settings instead of one, and swappable batteries on the G3Pro, which also has a longer battery life overall.
You can compare all three models' features and prices over at Theragun. The G3 and G3 Pro also come with a free charging stand worth £69 separately.
For more fitness hacks see our round up of the best fitness apps, and if you want to expand the fitness tools at your fingertips, here are all the places you can buy home exercise equipment in the UK.