Pliers-type (or 'gun') for removing the pins in watch bracelets, to remove or add links.
Used properly this is easy to operate - place the bracelet in the slot, carefully line the pin in the 'gun' with the pin in the bracelet, then gradually increase the pressure to see if the pin moves. However, do not use this if you are cack-handed. Some people don't line up the pins, they squeeze the handle suddenly and very hard, and they break both the 'gun' and the bracelet!