Are men and women both able to use SelectTech dumbbells and weights?

Absolutely.

With the SelectTech® 552 Dumbbells, the weight can be adjusted from 5 to 52.5 lbs (2.26 to 23.7 kg). From 5 to 25 lbs (2.26 to 11.3 kg) increments of 2.5 lb (1.13 kg) are used; from 25 to 52.5 lbs (11.3 to 23.7 kg) adjustments are made in 5 lb (2.26 kg) increments making it versatile enough for strength trainers of all abilities.

The SelectTech® 1090 Dumbbells can be adjusted from 10 to 90 lbs (4.5 to 40.8 kg) in 5 lb (2.26 kg) increments for anyone looking for a more intense workout.

The SelectTech® 840 Kettlebell can be adjusted from 8 to 40 lbs (3.5 kg to 18 kg) in the following increments: 8 lbs (3.5 kg), 12 lbs (5.5 kg), 20 lbs (9 kg), 25 lbs (11 kg), 35 lbs (16 kg), and 40 lbs (18 kg).

The SelectTech® 2080 Barbell and Curl Bar can be adjusted from 20 to 80 lbs. in 10 lb. increments.