Two eyepieces are included with the early Ross Lister Limb Microscope. One is an ordinary 'top-hat' Huygenian type with a power of approximately 8X, and has an outer diameter of 37.4 mm. The second is a Ramsden type, originally a micrometer eyepiece, but lacks its micrometer; this eyepiece allows focusing on the micrometer disc by sliding the top of the eyepiece up and down. As shown here below, it was pictured and described by Quekett in the first edition of his Treatise of 1848.