The Proximity Mine is a throwable in GTA 5 and GTA Online, listed here at a community-reported price of $1,000. Its datamined damage is 0, since it does its damage through an explosion rather than a bullet value, with an effective range of about 30 and a clip of 1. You place it on the ground or stick it to a surface and it waits, arming itself and detonating when a target walks close enough, rather than exploding on a timer or a direct hit like the Grenade or Sticky Bomb. That makes it a trap weapon, good for covering an entrance or a vehicle you expect company to approach, rather than something you throw directly at a target in the middle of a fight. Confirm the price at the counter since it is marked community-reported here. It takes a slot in the throwables wheel alongside the other explosives and needs no separate ammo type beyond restocking the item itself.
Pick it up in the world or buy it from Ammu-Nation.
The community companion for Grand Theft Auto VI. Database, maps, guides and tools for Vice City and the state of Leonida.