The Sticky Bomb Mod will cause your melee weapon to explode in a few seconds from being thrown, causing massive area of effect damage. The secondary explosion is identical to that of a Deo-Bomb, including the burning effect, but with just under half the blast radius. The blast always deals a fixed 5000 damage in addition to the normal damage dealt by the weapon, giving high-level Heroes a use for Knife variants such as the Diving Knife which do not level past 24.
The Sticky Bomb Mod has no effect on a weapon when it is swung normally rather than thrown. When thrown into an enemy, the weapon will disappear immediately, making it impossible to recover. However, Logan's Boomerang skill will allow him to recover the knife without removing the explosive from the enemy, effectively duplicating the weapon.
In Dead Island: Riptide, whilst the code for the knife to explode is there, this mod will instead cause the knife to start beeping after being thrown. Occasionally this beeping will form old cowboy trail tunes such as "Red River Valley" and "Oh, Susana" in ringtone form. This may be referring to the fact that Logan, the hero known for his thrown weapon skills, is from Texas, the state most well known for cattle-herding, rodeos, and most anything else that can be related to cowboys.
This mod is obtained in the main game from Antonio Margarete after finishing the side quest"Drowned Hope". This Mod is also available during Ryder White's Campaign, where you can obtain it during the Stolen Thunder quest, when you will go up a ladder and proceed to an upper area where you will find a survivor: on the left of a workbench table nearby you will find the Sticky Bomb mod.