Right hand thread. 3.75” diameter. Includes; adaptor 3/8”, 24 UNF FRH, 8 x 1.24 FRH nut, 8mm x RHM x 3/8” UNF, black spacer. Can be refilled with line without dismantling. Average time is 30 secs. Inner wall reduces the amount of dirt that can get inside the head. Lightweight and durable. Large eyelets to enhance line life.