What is the Type A or C?Is it a air conditioner or USB charge？

No.Actually，It is a pool filter cartridge.

A/C Pool Filter Cartridges are compatible with all above-ground pools and pumps that use type A or C filters, as well as type III filters. Filter cartridges replace Intex 59900E and 29000E filter cartridges.

Filters are compatible with several brands of cartridge filter pumps. Intex models: 28603EG (603), 28637EG (637R), 28635EG (635T), 604/G, 636T/G, 638R/G. Bestway models: 58384(E), 58387, 58388E, 58389, 58390(E). Summer Waves models: RX1000, RX1500, RP800, RP1000, RP1500, RP2000, SFS1000, SFS1500, SFS2000, CP2000-C.

Filter dimensions: 8" high x 4.25" diameter with a nearly 2" diameter center hole

What is the difference between Type A ,Type C and Type A/C pool filter?

The only difference between a type A and Type C is the internal diameter of the filter. The A/C Filter type is a hybrid which has an internal rim with a 1-3/4" internal diameter which will deform to 2" if the pump really needs an A filter.

There are some pumps houses that the A/C Filter will not work in - check the bottom of the table below for known incompatibilities. 

There are basically 3 critical dimensions in a filter cartridge; The length of the filter, the outside diameter of the filter end-cap and the inside diameter of the endcap. 

For Intex and Unicel filter sizes these measurements are as follows:

In fact, this A/C pool filter cartridge has been a very hot seller. It is sold on Amazon at a very low price. But you still need to be careful in the selection process. Here are some complaints from Amazon customers.

Inconsistent Quality and/or Poor Design Change

The filters I purchased from Amazon are the exact same model as others I have purchased from a local store. However, the filter cartridges I purchased from Amazon only have one internal support ring that is on center portion of the filter. The other filters that I have used in the past and purchased recently has three support rings to help the filter from collapsing on itself. The filters from Amazon collapsed on itself after only a few hours of use. Very poor quality control or poor product design change. I am not comfortable buying these without first being able to see with my eyes what version I am getting.

AWFUL!

These are the WORST filters I have ever used -Even with a sparkling pool, these stop working after an hour or two. And when we take it out to clean it, once you put it back, it won't work at all. We went through 3 of these brand new filters in one day; So disappointed in these, especially since it's the same brand as our pool.

Please pay particular attention to the support and membrane material of this cartridge. Poor quality supports are prone to collapse under high pressure. Poor quality membranes can lead to poor filtration results.

Zotee cartridges provide efficient filtration, with tight pleats enclosed in thick Dacron paper for enhanced performance.

The filters are made with premium quality polyethylene terephthalate fibers for advanced superior cleaning, as they provide crystal clear water filtration. Filters contain a durable hard plastic iner core that is collapse-resistant.

For use in pool pumps that range from 530 gallons per hour to 2,000 gallons per hour. For best performance, replace the filter every two weeks. Filters are washable easy to replace and clean filter cartridges with long service lives.

For maintenance, it's recommended to replace the swimming pool filter cartridge every 4 weeks. Alternatively, you can scrub the fabric with a cartridge cleaner tool and rinse it with a hose every 2 weeks.