Dumbbells. Dumbbell is a simple instrument to increase muscle strength training. Dumbbells have fixed and adjustable weights.

1. Dumbbell with fixed weight, made of pig iron, with an iron bar in the middle and solid balls at both ends.

2. Adjustable dumbbell, similar to a reduced barbell. The two ends of the short iron bar are sheathed with round iron pieces with different weights, and the length is about 40-45 cm.