Here's the information you need to share with your supplier to get the right blade.
Equipment - Provide your supplier with the make and model number of the saw. Mismatching blades to equipment will reduce the tool's operating life and efficiency, and could make it dangerous to operate.
Diameter & Arbor are needed so the blade fits safely on the saw.
The Material Being Cut determines the segment “bond hardness” of the blade required. Tell your supplier what material you will be normally cutting. Using the wrong “specification” will result either in premature wear or the tool losing its cutting edge and not cutting.
Quality is determined by diamond segment height, diamond concentration levels or diamond crystal quality. Ask your supplier about the different grades that are available.
You usually get what you pay for.
Free always comes at a cost.
Bigger is not necessarily better.
Purchase from reputable suppliers.
Always ask for referrals....