Dụng cụ tháo snap Polar H10 HRM (Unsnap Tool)

Polar instructions say to to remove the unit (they call it the “connector”) from the strap between uses, in order to preserve the battery life.  This tool wedges around the snap to minimize the strap bending which could damage it.  It makes the unsnapping process really easy, and the tool also fits to pry open the battery compartment.

Recommend printing with minimum layer height for the leg slope - or just for the whole thing - to smooth out the steps along the wedge incline.

Other than that; no special print settings needed, and any rigid filament material should work fine.