Check the listing for details. Male to Male Double Coupling Ring reverse macro Adapter 49-52. Condition: New. Listed at 10.23 USD. DESCRIPTION: Product Name: Double Male Macro Coupler Reverse Adapter RingMaterial: High Quality Aluminum AlloyApplication: Double Male Adapter Ring, For Micro Photography Or Refitting AccessoriesFeatures: External Thread At Both EndsColor: BlackFunction One lens can be reversed in front of another (for exampleThat's to invert the 52m filter lens to the 58m filter.So as to achieve the effect of shooting micro distanceNoticeBoth the focusing ring and the focusing ring on the positive joint play a role. The focusing ring not only regulates the magnification, but also affects the focus.Point; move the fuselage when focusingThe focusing ring on the front joint plays a focusing role, while the adjusting ring on the reverse joint does not.The reverse joint is50mm ,The focal length of the positive connector should not be shorter than 120m, otherwise there will be dark angle or even only circular image field.The shorter the focal length of the connector, the longer the set distance of the positive connector needs to be Package includes: 1XMale to Male Adapter for 49-52mm