board and board

board by board

board to board

board to board connector

board-to-board connector

on-board color alarm board

printed-circuit board(PCB)(PC board)

section for gangway board and diving board

3D sketching

Architectural freehand sketching

Architecture sketching

axonometric sketching

block sketching

bridge sketching

carbon stick for sketching

cartographic sketching

cartographical sketching

charcoal stick for sketching

cracking and sketching element