This is the Mec-Gar 10 round .45 ACP magazine for Tanfoglio Witness Large Frame pistols.
Will also fit the CZ 97 with minor adjustment, on which the Tanfoglio was based. The CZ 97 and magazines have been discontinued.
Mec-Gar are the industry leader in pistol magazine production, providing OEM manufacturing for many big names including CZ, Beretta and Browning.
Frame Size
Tanfoglio have two frame sizes. You can ID them from the magazine width.
This is the Large Frame size - magazines are approx 21.4mm wide at the rear of the magazine.