They’re made from a few common materials: plastic (including vacuform/hardened plastic), latex, polyester, and recycled polyester textiles.
Most use an adjustable strap at the back for a secure fit. Product listings also provide maximum head-size measurements, which in this selection range roughly from about 7 inches up to about 26 inches depending on the item.
Most listings specify eye openings or full-face openings; some masks explicitly note both eye and mouth openings to improve visibility and airflow.
Some include battery-powered effects such as LED eyes, sound/growls, or fans. Examples in the listings require 3 AAA or 4 AA batteries; some inflatable heads include a fan with a battery pack.
The water-squirting effect is described as activated by opening the jaw and uses an internal reservoir (water can shoot about 5 feet). LED or light-up eyes and roar effects are often triggered as the jaw is opened, sometimes in stages for increasing effect.
![Garvee [2PACK]Halloween Led Scary Mask -Purge Mask with 3 Lighting Modes for Cosplay Costume](https://target.scene7.com/is/image/Target/GUEST_12cb26e6-8940-430c-9a1f-4b7afa630672)
