Best-Lock is a LEGO clone brand. Their bricks from 2005 and earlier did not have the same dimensions as LEGO. A 1x1 brick is 20x20x20 LDU, not 20x20x24. A plate is half the height of a (Best-Lock) brick, or 10 LDU thick instead of 8. Studs are 5 LDU high, not 4, so a LEGO plate cannot be fitted on top of a Best-Lock piece (though a LEGO brick can).
In 2006 Best-Lock merged with Cobi, a clone company from Poland. Best-Lock now packages and sells Cobi components which are 100% compatible with LEGO under the Cobi/Best Lock label. The old different ratio Best-Lock elements are now collector's items.
CBL has landed the contract for K-Marts store brand (Just Kidz) line of construction toys and currently is distributed throughout the U.S. under this additional label. Apparently cbl has purchased designs and components from Oxford of Korea in order to rapidly supply Lego-compatible elements to K-Mart. At least the riot police officers in some of the police kits are wearing Korean national flag symbols on their riot gear.