Features: brand new and high quality Good handfeeling and 50million clicks long service life. As long as the original mouse is a rectangular three-pin straight foot micro move, universal Crisp feeling, medium and short stroke, compact rebound.Less lag than similar products, nominal all conservative life! The blue button 50M, longer than the ordinary 20M life, and even, feel crisp, very comfortable! Relatively more crisp, feeling a little less lag rebound,relatively slightly lighter! Specifications: Model:D2FC-F-K Mouse Micro Switches Life: 30 Million times Click Quantity: 4PCS Material: Plastic Packing Size:approx 5x5cm/1.97x1.97in Currently known to apply to the following mouse fretting changes:/ Micro soft Red Shark IO1.1 (left and right buttons)/ Micro soft Silver Shark IE3.0/ for RAZER full range/ MX Series / for Saturn Trackball/ for Mars Trackball/ Gseries/ Apple-G3 G4 G5 Note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-2mm error due to manual measurment. Package includes: 4 Pcs x Kailh Mouse Micro Switches (Without retail package)