Spawns a red marker that follows Isaac's path, with a delay equal to 11/15ths of a second. If Isaac is far enough away from the marker to not be directly underneath him, placing a bomb will teleport Isaac to the marker and cause the bomb placed at Isaac's original position to instantly explode.
Isaac can still take damage from his bomb explosions if he is too close to the marker.
Interactions
Remote Detonator: Placing bombs will still teleport you, but they will not explode until Remote Detonator is used.
Bomber Boy / Giga Bombs: Not recommended, as the increased explosion radius can make it more likely for Isaac to get hit by their own explosions, regardless of distance to the marker.
Best Friend / Mr. Boom: The bomb placed by these items will explode instantly and teleport the player to the marker.
Video Showcase
Trivia
Telebombs originated from an item developed by the user known as "melon" (renown for being one of the developers of The Devil's Harvest and Bertran) by using the api provided by Antibirth, a mod for The Binding of Isaac: Rebirth and predecessor to Repentance. The item is shown in footage made by melon, titled "telebombs antibirth api test".
Bombs upon pickup.
Remote Detonator: Placing bombs will still teleport you, but they will not explode until Remote Detonator is used.
Bomber Boy / 
Giga Bombs: Not recommended, as the increased explosion radius can make it more likely for Isaac to get hit by their own explosions, regardless of distance to the marker.
Kamikaze! / 
Bob's Rotten Head: Does not teleport the player when used.
Best Friend / 
Mr. Boom: The bomb placed by these items will explode instantly and teleport the player to the marker.
