This is the climbing kit that I used to ascend the mast of my sailboat. The kit has a 7:1 block and tackle that is hoisted to the masthead with the main halyard. The block and tackle is sized to reach the top of a 39' mast. There is enough line to ascend a mast that is 3 or 4 feet higher than mine. The kit consists of ~300' of 3/8" Sta-Set line rove onto a couple of 30mm Ronstan triple blocks, one of which included a becket. A 1" ID x 1/4" stainless steel ring is attached to each of the blocks for attachment of halyard, and harness. Left and right Jumar Ascenders are used with a pair of webbing ladders to pull on the down-haul line using either arm power or leg power. A Black Diamond Bod Sit Harness size large climbing harness is part of this kit. A large aluminum carabiner is included to attach the harness to the lower block. A Belay Device is included to provide a means to safely descend. The whole kit is stored in a black nylon backpack for storage aboard.
Using this kit, a person can hoist himself up the mast and lower himself down the mast. When I used this kit, I always used an additional 1/2" safety which was lashed to my harness and bound to the mast with a rolling hitch. I woud keep the rolling hitch tight and slide it up or down the mast as I moved.
The price for this kit is $150 US plus shipping. This item is located in Corpus Christi, Texas.