Lithium-Ion Battery

I bought one of the 20v 2A batteries to test fit for compatibility with several 20v lithium battery powered tools I purchased from a company called TACKLIFE, who recently went out of business/changed their name making things difficult to find replacement batteries for. I contacted Tacklife, who sent me to Fillpow brand on Amazon for compatible batteries, after a 12-month search, and after paying three times the price for the same battery from them (which worked) I then ordered one of these JCB batteries the following day. For a 3rd of the price, these JCB batteries feel heavier and stronger than the Fillpow brand, and they fit all 3 of the Tacklife tools I was targeting - the Impact Driver, Standard Drill, and Reciprocating Saw. Maybe this helps someone in a similar situation from randomly buying batteries that have 5 charging fins to check for compatibility.