When your little one latches on correctly, she will have your entire nipple in her mouth plus approximately one inch of the surrounding areola and breast tissue. (verywellfamily.com)
When your baby latches onto your breast correctly, he will have your entire nipple as well as some of the surrounding areola in his mouth. (verywellfamily.com)
The suction I think is pretty good it covers my entire nipple. (exclusivepumping.com)