The CBER precision modular boring system converts ER collet holders into precision boring systems. The system fits into ER20, ER25, ER32 and ER40 collet holders and is capable of boring holes from 0.035" to 1.700" in diameter. All CBER sizes have a standard 0.001" on diameter adjustment dial. The ER32 and ER40 sizes are also available with a 0.000050" on diameter adjusting dial. All sizes are available in standard and short lengths.