Austrian rabbi and ritualist; flourished at Vienna in the second half of the fourteenth century. He shared the rabbinical office at Vienna with Meïr b. Baruch ha-Levi (Jacob Weil, Responsa, No. 151). Aaron Blumlein and Shalom, rabbi of Wiener-Neustadt, were amonghis contemporaries. Two of his pupils were Isaac Tyrnau and Jacob Mölln. His collection of ritual customs ("minhagim"), with his notes, was published at Riva di Trento in 1559. The editor of Mölln's "Minhage Maharil" added in several cases some of the minhagim collected by Klausner. His responsa are referred to by Isserlein in his "Pesaḳim u-Ketabim" (No. 6).