protective board 12 can be substantially same as that of the second protective board 13 a connection between the first protective board 12 and the second protective board 13 can include a crease 15 a micro control unit mcu not shown and a wireless control chip not shown can be embedded in the protective board 10 the hand strap 20 can be riveted for example to the protective board 10 by a rivet 21 in another embodiment the hand strap 20 can be mounted to the protective board 10 by gluing or other means of attachment or integrally formed the hand strap 20 can include a fastener 22 with a hole 221 defined therein fig2 illustrates that the protective board 10 can define a camera window 121 to correspond with a camera of the electronic device 200 as shown in fig1 the second protective board 13 can include a second buckle 131 to correspond with the first buckle 111 as shown in fig1 the second buckle 131 can be magnetic in another embodiment the second buckle 131 can be a snap on button the second protective board 13 can be folded along the crease 15 towards the first protective board 12 then the latch board 11 can be folded along the crease 14 as shown in fig1 and towards the first protective board 12 thus the latch board 11 can be attached to the second protective board 13 and the first buckle 111 can be buckled to the second buckle 131 to lock the protective board 10 fig3 illustrates that the receiving portion 30 can include a bottom board 31 attached onto the first protective board 12 as shown in fig1 a first sidewall 32 a second sidewall 33 a third sidewall 34 a fourth opening 35 facing the.