The Mamiya RB67 Finder Viewfinder Protective Cap is a push-on cap designed specifically for the Mamiya RB-67 lens fitting. This cap helps to protect the viewfinder and ensure that it remains in optimal condition for precise and clear viewing when shooting with your Mamiya camera. Its durable construction and secure fastening make it a reliable accessory for photographers looking to safeguard their camera's viewfinder while shooting.