The BowFlex SelectTech 840 Adjustable Kettlebell sets out to solve a problem that almost every home lifter runs into, which is the growing pile of single weight kettlebells that slowly takes over a corner of the room. Instead of buying a separate bell for every load you want to train, this one unit uses a dial built into its base to change how heavy it feels, so a single kettlebell is meant to stand in for several. This overview is based on the current Amazon listing and the published specifications rather than any first hand use, and it is written to help you decide whether the concept suits your space and your training before you click through to the product page.
What it is
The SelectTech 840 is an adjustable kettlebell. Rather than fixing one cast weight into one handle, it pairs a kettlebell body with a base, or tray, and a selector dial. According to the published specification the unit adjusts across six settings that span from 8 pounds up to 40 pounds, listed as 8, 12, 20, 25, 35, and 40 pounds. You set the load by turning the dial while the kettlebell is seated in its base, and the mechanism locks in the chosen plates so the rest stay behind in the tray. The idea is that one product covers the role that would otherwise need six separate kettlebells, which is where the space saving pitch comes from.
Because the weight is held in a shell around a central handle, the shape stays broadly kettlebell like across the range, so you can press it, hold it in a goblet position, or use it for carries and basic swings. The listing frames it as a home training tool, so treat the weight numbers and the settings as the headline facts and confirm them on the current product page, since specifications can be updated by the seller over time.
Key features
The features that define this kettlebell, as described on the listing, are straightforward. It is a dial adjustable design, so changing resistance is a matter of rotating the selector rather than swapping separate bells. It offers six discrete weight settings in a single unit, which is the core of the value proposition. It ships with a base that both holds the unused weight and acts as the docking point for every adjustment. And it keeps a consistent handle and silhouette through the range so your grip does not change dramatically as you go heavier. Below is the exact product this overview covers so you can match the listing before you buy.
BowFlex SelectTech 840 Adjustable Kettlebell
An adjustable kettlebell that uses a dial in its base to switch between several weight settings in one unit.
Check price on AmazonWho it is for
This unit is aimed squarely at home gyms that want adjustable weight without surrendering floor space. If you train in a spare room, a garage corner, or a flat where a full rack of fixed kettlebells is simply not practical, the appeal is obvious. One base and one handle replace a short shelf of bells, which keeps the footprint small and the room tidy. It also suits lifters who like to move quickly between loads inside a single session, for example going lighter for a technical drill and then heavier for a strength block, without owning every weight in between.
It is a weaker fit if you already own a wall of fixed kettlebells, if you need very fine jumps between loads, or if you do high volume ballistic work where a dropped bell is part of the routine, since an adjustable unit with a mechanism and a base is generally treated with more care than a solid cast bell. Think about how you actually train before deciding that one adjustable unit is the right tool for your plan.
Strengths on paper
On paper the biggest strength is consolidation. Covering a range from 8 to 40 pounds in one unit means you are not storing, cleaning, or tripping over six bells, and the single base keeps everything in one place. The dial system is designed to make changes fast, which matters when you want to flow between movements without long breaks. The retained kettlebell shape is another quiet strength, because it means the carryover from a normal bell should feel familiar for presses, goblet holds, and controlled swings. For anyone whose main constraint is space rather than budget, a single adjustable unit that spans beginner friendly loads up to a reasonably heavy 40 pounds is a sensible way to cover a lot of training with very little clutter.
There is also a planning benefit. Because the settings are printed and repeatable, you always know exactly which load you are using, which makes it easy to log workouts and to repeat them accurately week to week.
Things to check
A few points deserve a careful look on the listing before you commit. First, confirm the weight range and the increments. The published specification shows six settings from 8 to 40 pounds at 8, 12, 20, 25, 35, and 40 pounds, and you should verify those exact numbers on the current product page, because the gaps between settings are uneven and fairly large. The jump from 25 to 35 pounds, for instance, is a big step, so if you rely on small, steady increases this is worth weighing up.
Second, note how the weight is changed. The instructions call for adjusting the kettlebell only while it is seated in its base, so plan your training space around having the base on the floor within reach, and do not expect to dial the weight up or down while the unit is in the air or away from its tray. Third, check the practical details that a spec sheet may bury, such as the overall dimensions, the handle width, the base footprint when stored, and the warranty terms. If swings and other ballistic moves are central to your training, look closely at how the listing describes suitability for that style, since an adjustable unit behaves differently from a solid bell. When in doubt, verify every claim against the current listing rather than assuming.
How it compares
The honest comparison here is not against another branded product, but against the alternative approach of owning a set of fixed kettlebells. A set of fixed bells is mechanically simple. There is nothing to adjust and nothing to fail, you can buy them in finer increments if you shop around, and you can grip, drop, and swing them freely without worrying about a base. The trade off is space, cost, and clutter, because matching the 8 to 40 pound coverage of this one unit could mean buying and storing several separate bells.
An adjustable kettlebell like the SelectTech 840 flips those trade offs. You gain a small storage footprint and a single purchase that spans a wide range, which is the whole point for a cramped home gym. In exchange you accept a base that must stay nearby for changes, a mechanism that asks for a little more care than a lump of cast iron, fixed rather than freely chosen increments, and a body shape that may feel slightly different from a classic bell. Neither approach is universally better. The right choice depends on whether your scarcest resource is space or the need for simplicity and fine load control.
Verdict
As an editorial read of the listing, the BowFlex SelectTech 840 is a logical answer to the clutter problem of owning many kettlebells, condensing a published 8 to 40 pound range into one dial adjustable unit that saves space and keeps the familiar kettlebell shape. The main things to settle before buying are whether the six fixed settings and their uneven gaps match how you like to progress, and whether you are comfortable adjusting the weight only in the base. If those fit your plan and your room, it is a tidy, repeatable way to train across a broad load range from a single tool. Confirm the current weight range, increments, dimensions, and terms, then check the current listing to see the latest details and decide for yourself.
This is an editorial overview compiled from the current Amazon listing and published specifications, not a hands on review, and it reflects no first hand testing of the product. ProductPickly may earn a commission from qualifying purchases made through links on this page.