It has a coiled spring at the top which has a Metal spike fixed through the middle, which secures it to a wall. There is a steel rod fixed to a lever which has a shaped handle at the bottom. Have a good look at the pictures to get a good idea of how it works, and to make sure that it will suit your needs. There is a certain amount of rust and corrosion, but it works nicely and I think that the rust is mostly superficial and looks worse than it is.
It's an unusual item, and a project well worth embarking on with a tin of Hammerlite and a wire brush. It measures 24.5" (62cm) from the top of the pulling arm to the bottom of the handle, and the diameter of the bell is 6" (15cm). The item "ANTIQUE VICTORIAN SCHOOL FARM ESTATE YARD BELL ON METAL SPRING WITH IRON PULLER" is in sale since Friday, June 28, 2019.
This item is in the category "Antiques\Architectural Antiques\Door Bells & Knockers". The seller is "5cterr" and is located in Frome, Somerset. This item can be shipped to United Kingdom, Antigua and barbuda, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Australia, United States, Canada, Japan, New Zealand, Israel, Hong Kong, Norway, Indonesia, Malaysia, Mexico, Singapore, South Korea, Taiwan, Bangladesh, Belize, Bermuda, Bolivia, Barbados, Brunei darussalam, Cayman islands, Dominica, Ecuador, Egypt, Guernsey, Gibraltar, Guadeloupe, Grenada, French guiana, Iceland, Jersey, Jordan, Cambodia, Saint kitts and nevis, Saint lucia, Liechtenstein, Sri lanka, Macao, Monaco, Maldives, Montserrat, Martinique, Nicaragua, Oman, Pakistan, Peru, Paraguay, Reunion, Turks and caicos islands, Aruba, Saudi arabia, South africa, United arab emirates, Ukraine, Chile.