Covering Space Puzzles
is a Nikoli puzzle genre.
Draw a loop between vertices of the grid.
Each clued number must match the number of edges surrounding the cell used by the loop.
Puzzle #58: Spin Frame (Slitherlink (Hexagonal))
Puzzle #54: Hexaspring (Slitherlink (Hexagonal, Even Lines))
Puzzle #53: Down The Line (Slitherlink)