Antimagic Grenade

This wooden sphere sloshes with liquid when shaken, and is carved with runes that sting when touched, but leaves no visible wound. Once armed, the device explodes into an Antimagic Field 10 feet around itself that lasts for 10 minutes. This area is divorced from the magical energy that suffuses the multiverse. Within the sphere, spells can't be cast, summoned creatures disappear, and even magic items become mundane.