High Yield/High Capacity 

120gams per each bottle

compatible with for the model of

Samsung SCX-4321 SCX-4521 SCX-4521F SCX4521F . 

 P/# SCX4521D3, SCX-4521D3 toner cartridge.  

The cartridge is very easy to refill. Takes less than 3 minutes to complete the job and SAVE, even you have never refilled a toner cartridge before. 

Easy to do instructions show where the existing factory fill hole is located.

You could open it with a small screwdriver or pliers. 

This toner is new in a factory sealed bottle and warranted to be free from defect, 100% compatible.