A 25 mm customizable stamp.  I included my pay up stamp we use for charity raffle tickets, as well as a blank stamp end to make your own.

To make your own personalized one open bambu studio and just add txt or an svg to the blank stamp bottom by right clicking the blank stamp.  Then go to add part, then svg on the drop down menu.  Size your svg to fit the blank mold then select a depth of 3mm.  You can also just add txt by selecting the blank model and then clicking the Ta text icon on the menu at the top of the screen or by Hitting the T key on the keyboard with the model selected.  When you have it all done make sure you right click the stamp model, select mirror, then choose along the  x access.  This will make sure your your stamp is facing the correct way on the paper.

To apply the stamp to the handle just use glue, personally I used a little hot glue and it worked perfect.