This mod can be purchased unranked from the Void Trader Baro Ki'Teer for 115,000 Credits 115,000 and 300 Ducats 300. Remember however that Baro Ki'Teer's stock changes with each appearance, and may not have this item available at every time.
Once the buff triggers, the secondary weapon must be reloaded to gain the double magazine bonus; it does not automatically double the current magazine.
Upon reloading, the extra magazine capacity is pulled from the player's secondary weapon ammo pool. If a player does not have enough reserve ammo to fully double the magazine, the magazine will use as much ammo as the player has.
When the ability ends, the surplus ammo in the magazine (above its normal capacity) is returned to the player's secondary ammo pool.
The timer for the buff is not reset if another melee kill is performed while it is active.
Although they are considered Thrown Melee weapons, this mod cannot be equipped on Deconstructor or Deconstructor Prime due to these weapons having no direct synergy with the player's secondary weapon.
This mod works well with secondaries with an alt-fire that empties the magazine into a single torrent (such as the Kuva Kraken and Tenet Detron) to charge up Mag's short-tap Magnetize bubble, causing it to deal extensive damage against pulled targets and resulting in a high-damage explosion at the end of its duration.
This mod synergizes with the Cycron and its Tenet counterpart, as the increased magazine capacity allows it to sustain its beam longer and at the same time quickly recharge its ammo due to the increased reload speed.
For a short time after Update 22.0 (2017-10-12), this mod could have been acquired via Transmutation with [PH] (standing for placeholder) in the title.