* Adjustment Range: 28-93mm, Shank diameter: 9.5mm, work great with electric drills

* The Carbide Steel Hole Saw are made of alloy steel with a sharp drill,so the hole saw will opens more evenly and smoothly,improve the trepanning speed

* Use triangular drills designed,can reduce cutting resistance excellent for making clean and accurate hole in thin place.

* Hole opener can drill 28-93mm round hole, general electric drill,Power drill. Do not use impact mode of drill or hammers