Answer's Nintendo Switch Joy-Con Boxing Grips Look An Awful Lot Like Knuckledusters: Made for boxing and fitness games.
Nintendo Switch Joy-Con Charging Grip Plus
I got my first system since N64. No, games yet, what should I play
Switch Joycon - Temu
✔Easy to use ✔High Quality ✔Perfect hand grips for Game Cards ★Package Includes: 1 *blue grips with strap 1*red grip with strap ★Service and Guarantee
Fitness Boxing Hand Grip Compatible with Joy Con Controller, Compatible with Nintendo Switch/Switch OLED Model 2021 Controller, Handle Grip for Switch
Fitness Boxing Hand Grip Compatible with Joy Con Controller
Nintendo Switch™ Joy-Con™ - Left & Right - Pastel Purple & Pastel
Random: Golf Clubs And 'Brass Knuckles' - Nintendo Switch
Nintendo Switch Lite Compatibility Guide: Which Games Have Issues
Nitro Deck review: the comfiest Nintendo Switch grip out there is
MoKo Hand Grip for Fitness Boxing Fist of The North Star, Upgrade