Review on HHIP 2007 0021: Advanced Interchangeable Counterbore Set for Precision Machining by Timothy Louis

It was rusty inside and the set screw holding the rail didn't go deep enough to hold the rail in place. Either the threads are not fully cut or rust has blocked the threads. Attempting to drive the set screw deep enough to engage the rail resulted in the screw becoming irreversibly wedged. Also, the guides, bits, and holder seemed to be of acceptable quality, but I couldn't cut anything with them.