The thumb grip provides better balance and grip convenience when holding the camera. With the thumb up, you can securely grip the camera and hold it in any position. The thumb grip has no interference to all the original operations of camera. It is easy to install, easy to control and no snag on straps or clothing. Aluminium alloy construction with black anodization, it is against corrosion and abrasion.
Prices for various thumb grips:
FujiFilm XT-1/2/3: $39.90
FujiFilm XT-10/20/30: $39.90
Sony A7M2/A7R2/A7M3/A7R3/A9: $39.90