The 1621 can be different weight capacities. My OEM one on my Wildcat was rated 12000 lbs. I switched it for a Moryde RPB rated 16000 lbs. Both the OEM and the replacement are Lippert 1621 compatible.
So if the one you are being offered has at least the same or better weight rating you should be ok.
2016 Wildcat 295RSX - 2015 GMC 2500HD DblCab Duramax/Allison 4x4 Z71 6.6' Bed
Maxxis 235/80/16E; AirBags w/AirLift1; mor/Ryde Rubber Pinbox; Andersen UltimateII Alum. 5erhitch on Reese Flipball w/Curt 4" offset; LCI Ground Control3; King Dishtailgater; Traveling with 10' Portabote;