I would offer another recommendation: the Thrunite Ti3 it's ~2 3/4" in length. Some other specs -
LED: Cree XP-G2 R5
Battery: 1 AAA battery
Dimesion: 70mm(length)*14mm(head diameter)
Weight: 12 gram without battery
Waterproof to IPX-8 standard
Firefly: 0.04 Lm(115h), Low: 12 Lm(6.3h), High...