This whistle includes the phone number for the LUCE hotline (https://www.lucemass.org/), which is used in Massachusetts, USA. The text is raised on the model, so you can print with a color change for better visibility of the phone number. I'm including a 3mm and 4mm version. The 3mm can print okay if your printer is dialed in well, but sometimes my bottom layer is under-extruded, so with only two layers, the bottom isn't airtight. The 4mm version prints consistently for me, but it takes longer and uses more material. The text is raised by 0.4mm, so it prints in two layers on 0.2mm, which is enough for it to show up clearly without being obtrusive.