BowFlexSelectTech 840 Adjustable Kettlebell

Overview

The SelectTech 840 applies BowFlex's dial system to a kettlebell. Turn the dial while the bell sits in its base and you get one of six weights (8, 12, 20, 25, 35 or 40 lb), so a single bell replaces six. The handle is 28 mm thick, a plastic shell houses the metal weight plates, and BowFlex backs it with a two-year warranty. It lists at $149.

What reviewers say

The consensus is warm but qualified. BarBend's reviewer says he honestly enjoys it despite the plastic and the 40-lb cap, pointing to fast adjustment and value. Garage Gym Reviews concluded that for most people getting into kettlebells it's the best of the adjustable options, and its written review gives adjustment speed a perfect score.

The knocks are consistent: the shell is taller and more oval than a classic kettlebell, the handle is thinner than the roughly 35 mm common on standard bells, it isn't built to be dropped, and 40 lb is light for strong lifters. In Strength & Steel Reviews' 2025 showdown, the BowFlex won on convenience while the cast-iron Yes4All won on toughness and price.

Who it's for

Beginners, busy home exercisers and anyone doing conditioning circuits, swings, goblet squats and rows at moderate weights without room for a rack of bells. It's less suited to heavy swings, high-rep snatches or CrossFit-style abuse.

Bottom line

For convenience per square foot, nothing beats it at this price. Buy it for what it is, a space-saving tool for beginner and intermediate training, rather than a replacement for a set of cast-iron or competition bells.