Stand-up bases allow a wide variety of blocks to be held upright, swivel freely, or pivot so lines have a fair lead under load. Ball-and-socket bases let blocks articulate up to 45 degrees and swivel freely. The 460 and 461 bases have stainless steel reinforcement plates to handle the high load capacities of 57 mm and 75 mm Carbo blocks. Bases may be fitted with springs, but blocks won’t hit the deck without them. The 061 stanchion mount base attaches blocks to 22 mm or 25 mm (7/8" or 1") stanchions or pulpits and is often used to lead furling lines to the cockpit. Allows blocks to swivel and pivot for fairleads. Use the 1634 stand-up base with Midrange blocks and 57 mm or 75 mm Cruising ESP blocks. The block headpost fits into the socket without a shackle. The low-profile design is ideal for mastbase and halyard lead blocks. Springs support blocks on padeyes, eyestraps, bases, and traveler cars, and prevent blocks from hitting the deck.