Question: [Tuesday, 1st MarCheshvan 5783]
I sometimes wear a waist pack/pouch when I go out and would like to know if I may wear it during Davening.
You should not wear the pouch during Davening Shemoneh esrei.
Explanation: The Rambam rules that one should not Daven with an Afundaso. Some interpret this to refer to an undershirt, while others interpret this to mean a waist money pouch. It is unclear as to which of the to is the correct interpretation, and the Poskim conclude to suspect for both. Hence you should not wear a wait pack/pouch for Shemoneh Esrei.
Sources: See regarding not wearing the Afundaso: Admur 91:5; Michaber 91:5; Rambam Tefila 5:5; See regarding its definition: Rashi Brachos 54a; Kaf Hachaim 91:21