This is a Macro Photo Lens MP-E 65mm 1:2.8 1-5x

Features
Focal length and maximum aperture: 65 mm f2.8
Lens construction: 10 elements in 8 groups
Diagonal angle of view: 18°14''
Focus adjustment: Manual
Closest focusing distance: 0.243m 5X
Filter size: 58mm

A unique manual-focus lens designed exclusively for macro shooting

This is the first macro photo lens designed to achieve a high magnification greater than 1x without additional accessories. It is ideal for small subjects. The newly designed optical formula and UD-glass elements suppress chromatic aberrations which become apparent at high magnifications. For flash photography, Macro Ring Lite ML-3 can be attached to the lens.