They are regulation golf-ball size, listed with a diameter of 1.68 inches.
Available package sizes include single packs of 6, dozen packs of 12, and larger recycled practice mixes of 100 or 600 balls.
Descriptions emphasize increased distance and 'explosive' velocity, improved control and a soft feel around the green, and mention lower spin or softer compression to aid distance and feel.
Shells listed include ionomer, urethane, and resin; fills/cores include rubber and polybutadiene, and some listings state 'no fill.' Materials vary across listings.