 Complete the following phrase:  The 506th Heavy Panzer Battalion ; abbreviated: s.Pz.Abt. 506 was a german heavy Panzer Abteilung independent battalion-sized unit equipped with Tiger I tanks until 28 July 1944. During the period from 20 August to 12 September 1944, it was re-equipped with a full complement of 45 Tiger Ausf. B tanks. Some of the first Tiger IIs delivered to the 506th were examples fitted with the early production turret. The battalion saw action on the Eastern and Western Fronts during World War II. As with other German heavy tank battalions, it was attached as needed to larger formations. The 506th was unique in being the only Tiger battalion to include a fourth company. , equipped with Tiger I tanks, was consolidated with the 506th in 1944. It was also unique in that it regularly received new vehicles and replacements from other units to maintain a full complement. The unit served until the collapse of the 