Fit for 6.7inch Mobile Phones or under 6.7inch:The internal size is about 16.6*9*1.58cm (6.53 * 3.54 * 0.62inch), Compatible with i-Phone 15 /15Pro/15Plus/15Pro Max/14/14Pro/13Pro/13 /12 Pro Max /12/11/X/XR/XS/8 Serials, Sum-Sung, Hua-wei etc.Cautions: Folded phones or over 6.7inch not support. 50 days long working Time with Auto-Timer: Max working Time Reach Up 50 Days Once Full Charge. Max setting Time is 99hrs and 59mins for Your different Needs,Super standby time over 90 days. Mini Portable and Durable Design:Easy-Carrying ,Lightweight, Fashionable Phone lock box , Make good Habit for Kids,Students,Adults. More respect and Love by lock box ,Make their Focus Back . Only Emergency Calling Support: The opaque box makes you won't pay attention to the notifications on lock screen.You only can use Earphone,Siri or Small Holes to answer/hang up the calling or listening to music. Fault-tolerance Mechanisms:Press power button 2 times to confirm the time setting, and there will be a 10 seconds countdown "hesitation period". At the "hesitation period", you can cancel the setting by clicking the power button one time, or it will be locked. As a last resort, there can only be used five in a lifetime for emergency unlocked, please use it with caution.