THE VELCRO OPTION IS $1 MORE THEN THE BUTTON OPTION. If you are getting a velcro option please see the home page for additional information. It is better to get the velcro on the second purchase because it allows for a more accurate measurment. if you get the velcro option please put the measurement down below in the customer text box or just message me. Measure from where the belly piece attaches to the diaper all the way down the strap to the button hole you use for a particular feather baby.