Citrus reamer
A citrus reamer (sometimes, a "lemon reamer" or simply a "reamer") is a small kitchen utensil used to extract the juice from a lemon or other small citrus fruit.
It consists at one end of a convexly tapered conical blade, with deep straight troughs running the length of the blade. The very tip of the blade is often a smooth spike. The other end is a cylindrical handle. The blade may be made of wood, plastic, or metal. The handheld reamer, which is held in one hand while the lemon or lime is held in the other, is a relatively new adaptation of the traditional glass or plastic citrus reamer( with a juice rim) that was placed on a table and pressed downward.
To use a hand reamer, the user first slices a chosen fruit in half with a knife along its equatorial midsection. Grasping the fruit in one hand and the reamer in the other, the user first pierces the exposed flesh of the fruit with the tip of the reamer blade, then grinds out the inside with a twisting wrist motion until nearly all of the juice is extracted. This dislodges the seeds and some amount of pith, so the juice must generally be strained before use. It works well with limes and lemons, but larger citrus fruit (grapefruit in particular) requires a larger device.