This listing is for a complete quick-release objective lens system by R & J Beck Ltd of London. This particular design of quick-release is called Beck-Sloan and is contained in a fitted wooden box with instruction sheet and comprises.
4 quick-release objective mountings (RMS thread) - a nose-piece adapter that fits into the optical tube - RMS thread - a set of instructions - 3 R & J Beck objective lenses of various types and magnification. 32mm NA 0.15 - 5x magnification - 16mm NA 0.28 - 10x magnification.
4mm NA 0.85 uncovered - 40x magnification. This equipment is therefore intended for use with both bright-field and incident illumination applications. I've tried to demonstrate in the listing photos how the quick-release system works and I've shown the adapter unit being fitted to a Watson Service optical tube. Once the adapter is in place the lenses with their mounts are located by twisting the thumb-screw on the adapter unit to secure in position.
Also interesting to note broad-arrow markings on some of the mounts indicating previous use by government or military. All-in-all a nice easy-to-use system for those who prefer objective lenses on quick-release mounts. This item is in the category "Antiques\Science/Medicine\Scientific Instruments". The seller is "arcboutant" and is located in this country: GB. This item can be shipped to United Kingdom, Antigua and Barbuda, Austria, Belgium, Bulgaria, Republic of 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, Bahrain, Canada, Brazil, Japan, New Zealand, Israel, Norway, Indonesia, Malaysia, Mexico, Singapore, South Korea, Switzerland, Taiwan, Thailand, Bangladesh, Belize, Bermuda, Bolivia, Barbados, Brunei Darussalam, Cayman Islands, Dominica, Ecuador, Egypt, Guernsey, Gibraltar, Guadeloupe, Grenada, French Guiana, Iceland, Jersey, Jordan, Cambodia, Saint Kitts-Nevis, Saint Lucia, Liechtenstein, Sri Lanka, Macau, Monaco, Maldives, Montserrat, Martinique, Nicaragua, Oman, Pakistan, Peru, Paraguay, Reunion, Turks and Caicos Islands, Aruba, Saudi Arabia, South Africa, United Arab Emirates, Chile, Bahamas, Colombia, Costa Rica, Dominican Republic, Guatemala, Honduras, Jamaica, Kuwait, Panama, Philippines, Qatar, El Salvador, Trinidad and Tobago, Vietnam.