Orbit 62056 One Outlet Single-Dial Hose Faucet Timer

Would someone kindly explain why this Orbit with a brass connector gets lower ratings than what looks to be the same timer with a plastic connector?

Can this be set for any day of the week, ie, every 4, 5, 6 or 7 days? My DIG, cannot. It jumps from day 4 to 7.

how often do I need to replace batteries?

Hi, Could you please let me know what size are the threads of the ends of the timer? Thank you.