Caution Notice: It does not replace the core electronics. Any existing defects of the electronic core will not be fixed by the shell replacement. Please check the appearance and shape of your key and the number of buttons before purchasing and the applicable model. Features: Good replacement for a key with the broken key case. It is the same buttons and the same key blade (if there is one) as the original one, you can use it as usual after replacing the key case. Function: Protects your car key from scratches and damages effectively. Easy to install, simple and fast. This is a non-OEM product, accessory only! Specifications: OE Number: CWTWB1G767 Type: Key Case Color: Black, Silver Tone, Red Dimension: 6.5x3.5cm / 2.56"x1.38"(L*W) Buttons: 4 Key Buttons Materials: Plastic, Metal Button Function: Lock Key, Unlock Key, Panic Key, Open Trunk Key Battery/ Transponder Chip/ Electronic: Not Included Fitment:for Smart Fortwo 453 Forfour 2015-2017How to Install: Open your existing key. Remove internal components and transfer them to the new replacement. Screw/click the key back together. Check if everything is working fine. Package Includes:1 x Key Shell Case (Key Case Only. No Electronic Internals)