This trimmer head come from biggest garden tool manufactuer which OEM for Stihl,Makita,etc..
The quality is the best.
Perfect for residential or commercial applications.

Features:
.Less 30 second line twist loading–easy load system, no disassembly required.
Simply feed the line into the eyelet, give the head a twist and it’s ready to go.
.Takes all trimmer line shapes from 2.0mm to 3.2mm diameter.
.Bump Feed Mechanism.
.Italian Designed and Engineered.
.Mounting: Thread hole size: M10 x 1.25 Left Rotation Way.
.Color: orange
.Easy to fit, just screw on to your existing trimmer (left hand thread).
.Vibration free operation.

.Suit for straight-shaft garden pole tools products.
Please note: This will not suit most curved-shaft trimmers or any trimmer which uses a separate bolt to secure the head in place.

This head has a female thread designed to screw onto a threaded bolt as shown in the picture.
Thread fitting: M10 Left hand
You will receive one trimmer head