If you always wear a belt to work, school, or daily activities, then this is the product for you. The BeltnGo fits all pumps. Its the same size as our ClipnGo just without the clip. the loop is made of webbing and accommodates belts up to 4"wide. If you wear our ClipnGo and just put your belt thru the clip, you can only fit belts up to 1"wide. The BeltnGo allows belts up to 4"wide. The BeltnGo needs to be worn with a belt but lays flat against the body. A great pump case if you wear a belt everyday.