BRAINGAIN black adjustable kettlebell with quick-lock mechanism and cast iron weight plates

Rank #2 in Best Adjustable Kettlebell 2026: What 7-in-1 Really Means

BRAINGAIN Adjustable Kettlebell 18kg 7-in-1 with Quick-Lock Mechanism, Cast Iron

£99.99 4.5 from 40 Amazon ratings
Check price on Amazon

Price and rating as shown on Amazon when we collected them. Both change.

BRAINGAIN's 7-in-1 costs £99.99 and is the only adjustable kettlebell in this comparison with a stated warranty: two years, from a UK brand.

It adjusts from 4kg to 18kg in seven steps, which is a real increment of about 2.33kg per step.

How those 40 ratings break down

An average hides its own shape. This is the spread behind the 4.5 stars.

5 star
76%
4 star
16%
3 star
2%
2 star
0%
1 star
6%

Specification

Exactly as published on the Amazon listing, field for field.

Range as stated 4kg to 18kg
Increment About 2.33kg
Warranty 2 years, UK
Weight at the top 18kg
Ratings 4.5 from 40
Handle diameter as listed Less than 27.27 inches

What buyers actually say

Quoted from customer reviews on Amazon

Verified purchase

“Thank you BRAINGAIN for proving such a great product and the versatility is brilliant. Kind regards Anowar Idrissi”

Mr Anowar Idrissi
Verified purchase

“This is really good quality and great for people who are moving up with weights giving so much flexibility. I bought it specifically for when I go away as it saves loading the car with lots of different weights. I was incredibly pleased with it.”

Julie M

What it is up against

The rivals it was ranked against in Best Adjustable Kettlebell 2026: What 7-in-1 Really Means.

Questions people ask

What does it weigh when empty?

4kg, which the listing states as the starting weight of the adjustment range.

What is the step size?

About 2.33kg. Seven weights across a 14kg range, and the increment is never stated as a number.

Who makes it?

BRAINGAIN, a UK brand that names itself in the listing and offers a two-year warranty.

Is the handle the width stated?

No. The field reads 27.27 inches, a double unit conversion; a kettlebell handle is 3 to 4cm.

Why is it second rather than first?

The warranty is the best here and it costs £60 less than the pick, but 40 ratings against 71 makes it the thinner evidence.

How many ratings does it have?

40 at the time of collection, averaging 4.5 stars, with 76 per cent five-star and 6 per cent one-star.

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