Purotwist 3000 and 4000 replacement filters with quick change, twist pre and post-filters Q5633 and Q5605.
They are not similar to other standard 10" filters.
Omnipure original organic cellulose under sink filters that are compatible with some others like the GREEN Gro 50EN Reverse Osmosis Systems.
 
Each filter represents a different stage of the water purification process. Pre-filters and post-filters in RO systems typically last around 8 to 12 months between changes, while the original organic RO membranes ( not included)can last up to 5 years.
 
Stage 1-
 
Q5605 sediment filter is the first filter installed in all Reverse Osmosis water filter systems, It removes large and fine particles from drinking water, such as sand, dirt, silt, and rust particles. 
This allows for better performance of all the following filters, such as Carbon Block or GAC filters.
 
The micron rating is 5 microns.
the dimensions are (9 7/8")
 
Replace every year depending on the water quality.
This filter meets NSF Standards and Regulations and is wrapped and sealed.
 
Stages 2 and 3
Q5633 Organic Original Activated Carbon Block Filter is made of fine coconut shell carbon. It removes odors and tastes of many organic compounds, especially chlorine. Because these filters are made of packed carbon (forming a cylinder block), they offer much finer filtration of suspended particles and dirt.
 
The micron rating is 5 microns.
the dimensions are (9 7/8") x 2.5"
replace every year depending on the water quality.
This filter meets NSF Standards and Regulations and is wrapped and sealed. 
 
Stage 4- ( Not included with this set of Filters)