The Marcrist Professional Diamond Drilling Extension is a metal extension which fits all machines and diamond cores with a 1 1/4 inch thread. It is a 200mm length x 1 1/4 Inch UNC (F) x 1 1/4 Inch UNC (M) extension for dry and wet drilling. This extension is useful as it allows the user to drill a larger hole without changing core. Durability was key to marcrist when designing the extension, as a result the product was made from hardende metal and is corrosion resistant giving it a longer life time. Features & Benefits • Hardened for durability • Balanced for concentricity • Corrosion protected Specifications • Length: 300m