I have one of the old design Polaris boxes on my 850. Not big enough for what I want though. I am going to have to adjust how I pack the stuff I take with me. FPD has a new designe Polaris box on his and I do like that. I had a Moose one on my 600, but that leaked water, dust and just about everything else. Tried and ATV Tek one on the 850 and that was too small also. Along with the soft material being harder to clean.
With the Polaris box you have the lock and ride so you don't have to drill holes in it to mount it.
Mine: 2018 Sportsman 850SP - 26" Bear Claw HTRs on OEM steel wheels(I really don't like the Aluminum ones)
Polaris Hand warmers, Mirrors.
Hers: 2007 Sportsman 500 EFI, Polaris Winch, 26" Bear Claw HTRs on Moose 427x Wheels. QSC Clutch Kit, Hand Warmers
2001 Magnum 325 MOSE 12" rear wheel conversion. 25" Sedona Coyote tires
2001 Magnum 325 Warn winch and Moose 60" plow
2017 Polaris Ranger 1000XP - Roof and front glass
SOLD 2004 Sportsman 600 Twin