Orion 7398 2.1 Pound Counterweight for EQ-1 and Min-EQ Mounts Small 2.1lb counterweight for proper balancing of lighter loads on the EQ-1 or Min-EQ equatorial mounts Narrow weight diameter eliminates contact with EQ-1M motor drive, allowing full rotation of the Right Ascension axis Ideal for balancing relatively lightweight DSLR camera and lens combinations on the EQ1 and/or Min-EQ equatorial mounts Counterweight measures 46mm (1.8") in diameter and 85mm (3.35") in length