Cement filled dumbbell design with circa 4kg of wieght

• print 2x of the model
• get an m6 rod with x4 nuts
• fill the mold with cement and let it dry
• add the nuts from both sides and screw in the rod
• add the grip handle ( print in fuzzy mode )
• screw in the other half of the dumbbell

works well i have been using it for a year now