Harp-M ★
Harp-M ★ is a legendary bow.
A special squid capturing device with electric neutralizers - to defeat, but not over-defeat.
An upgrade for 
Alta Harpooner.
Ingame
Radiomessages on pickup:
- You’ve just picked up an alta weapon, or an “energy tool”, as they call it. According to my database, these usually have an extended set of features. I suggest reading its description.
Sources
Can be obtained via 
Technical Information
- In-game ID:
ct_alta_harpooner-upgrade - Power:
3.85 - Rarity:
Legendary - Tags:
alta,legendary,ranged,uncommon,upgradeableWeapon,weapon - File:
/items/active/alta/tools/hunt/harpooner/ct_alta_harpooner.activeitem