Some sleeves use a single line inside the sleeve to pull the sleeve off the sail. If this line is loose in the sleeve (most are), the sail can wrap around the line and be damaged by the line rubbing the sail. Some designs put the line in a pocket and tie the line to a bottom ring or plastic bell. This results in lifting the bottom ring from only one side and it will cock and jam.
Some manufacturers attach a plastic bell or flexible cone to the bottom of their sleeves. This is supposed to make the sleeve easier to pull down because of the shape and smooth surface. The truth is that resistance to pulling any sleeve down comes from the wind blowing the sail away from the boat, not friction between the sleeve and the sail. The bell has several disadvantages: it adds weight aloft, it is bulky and covers part of the sail head, its pie plate edge can abrade the sail when packed in the sail bag, and finally, it will often be dangerously swinging at eye level while raising or lowering the spinnaker. The soft cone deforms under load and may not have the strength to reef the spinnaker. Neither the bell or the cone is any better than our smooth dacron covered stainless steel ring for furling the sail. The key to getting any sleeve down is to collapse the sail.
So why is the Chutescoop your best buy?
Key elements in our design are ease of operation, strength, and low cost. Our redesigned sleeve features one large pocket that contains two lines on the outside of the sleeve. The sail cannot contact any line.