C&K KMR231GLFS is a tactile micro switch, specifics:

• Circuit: Single Pole, Single Throw Normally Open (SPST-NO),
• Shape: rectangular, 
• Button: Sealed soft polymer with a satisfying tactile click,
• Pins: 4 pins (2 at each end) and a ground pin that can be left unsoldered if the PCB does not have a contact for it,
• Contact Rating: 0.05A at 32VDC,
• Actuator Type: Standard,
• Mounting Type: Surface Mount,
• Height off PCB: 2mm (its exactly 1.90mm),
• Width: 3mm (its exactly 2.80mm),
• Length: 4mm (its exactly 4.60mm),
• Switch Function: Off-Mom (momentary),
• Operating Force: 300gf,
• Mechanical Life: 150,000 cycles (should be the last time this operation is needed),
• Temperature Range: -40°C to 85°C.

How to replace the button switch in your car remote lock key fob:

1. Gently open your existing key fob and look at the circuit board.
2. Compare the switch with the images shown in this listing:
3. If its rectangular, has 4 pins and has a rubbery button that is black and oval shaped, its a C&K brand switch
4. Place your order and the buttons will be with you in a few days
5. With clean hands, compare them and be sure (just return them to techSupp in a saleable condition, if they are the wrong ones)
6. Plenty of flux on and desolder the old button 
7. Place the new button in place and solder on
8. Test it, 
9. Smile you saved a fortune and relax that new button is made to last 150,000, C&K / Littelfuse is the brand automobile / car / van makers use; money spent wisely.  You deserve a nice cup of tea.