Dumbbell, Barbell: This genius workout equipment merges the dumbbell and barbell into one versatile free weight set. With 16 weight variations per mode, from 4 lb to 90 lb for the dumbbell and 5 lb to 90 lb for the barbell, it unlocks endless possibilities for your free weight exercises Quick Weight Customization in Seconds: Thanks to the quick-adjust handle, this adjustable dumbbell allows you to customize your workout in a flash. Switch between 16 different weights in seconds by simply twisting the anti-slip handle. The clear dials for each mode make adjustments effortless and intuitive Dual Safety Lock Mechanism: This adjustable dumbbell features a dual-lock system that ensures stability and balance, keeping your workouts safe and steady. The weight adjustment kicks in only when the dumbbell/barbell is securely on the tray, eliminating any chance of accidental operation Space-saving Storage: You can effortlessly achieve space-efficient storage with this 2-in-1 free-weight set. Easily store it beneath a workout bench or on a garage shelf post-strength training, saving considerable space compared to owning 32 separate weight sets Enhanced Safety with Non-slip Handle: To offer a secure grip during your workouts, this free weight set features anti-slip convex textures on the dumbbell handle and knurling on the barbell handle. This combination of materials enhances grip strength and provides comfort during intense workouts About Weight Adjustment: To adjust the dumbbell/barbell weight, fully insert the handle into the base (in the lowest position) before turning it. Align the red arrows with the numbers on both dials until you hear a "click-clack" sound, confirming the adjustment. If the red arrows aren't aligned, reset the handle and adjust it again