Most are designed for newborns up through about 36 months; some items target 0–6 months while others start at 6 months or older.
Many musical or light-up gyms require batteries (commonly 3 AA), while simpler play mats and activity systems are often battery-free.
Care varies by model: many can be spot- or wipe-cleaned, and several mats or pads (or their removable components) are machine-washable.
Most activity gyms and larger play systems require adult assembly; a few models are tool-free or fold for easier storage and transport.
Sizes vary from compact activity tables with roughly a 20-inch footprint to larger mats and gyms about 34–50 inches in length or width, ranging from small tabletop stations to room-spanning play areas.
Some systems fold for easier transport and storage; toy bars or keyboards often detach for take-along play, and a few sets include built-in storage or removable components for tidier cleanup.