Apollo is a tenkeyless (TKL) keyboard Printed Circuit Board (PCB) which main feature is the per-key RGB lighting. This particular variant, 87H (short convention for 87 keys Hotswap), features an 87-key layout with Kailh hotswap sockets and supports a "default" TKL layout, that is, a 6.25 units spacebar, no split backspace or right shift, and ANSI-only enter.
Go to the Acheron Docs for the Apollo87H documentation.