The Panasonic AJ-HPX3000 is a shoulder-mount P2 HD broadcast camcorder introduced in 2007, marketed as Panasonic's first master-quality P2 camera - the wording behind Master Grade in used listings.
Three 2/3-inch full-raster 1080 CCDs recording AVC-Intra 100 (a P2 first) and DVCPRO HD to hot-swappable P2 cards, with a B4 bayonet for broadcast lenses, FILM-REC gamma, genlock and HD-SDI.
A milestone of the tape-to-solid-state transition: 10-bit intra-frame 1080 onto memory cards in 2007, years before file-based acquisition was universal; today a legacy piece for P2 houses and collectors.
Used buying: treat as legacy broadcast kit - check the hour meter and all P2 slots, remember P2 cards are a significant extra cost, verify whether a B4 lens and viewfinder are included (many ex-broadcast bodies are stripped), and expect asset engravings on ex-fleet units.