Fists icon in Contract J.A.C.K
Fists in Contract J.A.C.K or Holster Weapon as it's called in The Operative: No One Live Forever is a last-resort "weapon" of having Cate Archer or John Jack attack the enemy with their bare hands. (With Cate doing a mix of punches and Karate chops while Jack only punches.)
In the original No One Lives Forever, Cate's unarmed attacks are fairly weak with even weak enemies able to take a large amount of punches without going down, Cate's punches are more effective if done from behind on an unaware enemy but if you plan on attacking foes in melee, it is a better idea to instead bring the Barrette as it's poison dagger mode is far more effective in combat than Cate's unarmed punches.
In No One Lives Forever 2: A Spy in H.A.R.M.'s Way, Cate has lost the ability to attack with her bare hands and must instead use melee weapons for melee combat.
Punching returns as the Fists in Contract J.A.C.K with a notable increase in damage compared to the original game though it's still advised to only be used as a last-resort.