409 Astro Pneumatic Quick Change In-Line 4'' Cut-Off Tool is designed with a quick change button on the housing that locks the motor for easy disc changes and the in-line design allows for straighter and naturally consistent cuts. 409 Astro Pneumatic Quick Change In-Line 4'' Cut-Off Tool features a 3/4HP Motor and a 4'' size for maximum cutting capacity, a lever lock safety guard that quickly and easily adjusts. 409 Astro Pneumatic Quick Change In-Line 4'' Cut-Off Tool works well with most 3/8'' and 5/8'' hole cut-off wheels and includes one 4'' cut-off wheel.