Schaefer Marine 73-45 Jiffy Reef Stainless Slide with 7 series Aluminium Block and Bail with Polyethelyne Slide Liner for Track Size 1-1/4" x 3/16" (32mm x 5mm). Jiffy Reefing allows an entire "slab" to be quickly removed from the mainsail to reduce sail area and power in "heavy-air" conditions. With the mainsheet and main halyard eased, Jiffy Reefing lines pull the aft reef grommet tight to the boom. A separate reef line attached to the forward reef grommet is then tightened, pulling the sail tight and flat at the gooseneck. The halyard is then tightened and the mainsheet is trimmed with a new reduced sail area. This Jiffy Reef Block and bail has Polyethelyne slide liners held "captive" within the stainless slide to help reduce breakage common with other protruding liners. This adjustable slider has a welded bail and rides on a boom-mounted track to provide proper dead-end attachment point location fore and aft. This block slide leads the line forward along the boom to a spar mounted jam cleat.