Put the key directly above the skill key, and trigger skills by touching metal or silicone parts. Touch the metal ball through the electrostatic induction principle and trigger the skill under the gamepad trigger. And if the human skin touches the metal cap or conductive silicone sucker, it will trigger the skills under the gamepad trigger. They are applicable to mobile phones, tablets, any mobile games. The aim fire button can make the game operation more convenient and simple, and save operation time to enjoy the fun of the game. Item Name: Gamepad Trigger Material: Metal, Gamepad Trigger Features: High Sensitivity, Strong Suction, Durable Size: 1.5cm x 1.1cm x 1.1cm/0.6" x 0.4" x 0.4" (Approx.) Note Due to the light and screen setting difference, the item& 39;s color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Include 2 x Gamepad Triggers