A stopgap upgrade to the kv series was the short-lived kv-85 or objekt 239. This was a kv-1s with a new turret designed for the is-85, mounting the same 85 mm d-5t gun as the su-85 and early versions of the t-34-85. Already-high demand for the gun slowed production of the kv-85 tremendously, and only 148 were built before the kv design was replaced. The kv-85 was produced in the fall and winter of 1943-44; they were sent to the front as of september 1943, and production of the kv-85 was stopped by the spring of 1944 once the is-2 entered full scale production