How about this pulley?
This double pulley can be used for backyard zip lines/swing seats/baby trampolines/setups, dog running ties, climbing, weightlifting, rescue, bungee jumping, downhill, aerial work or other outdoor adventures.
The material is made of high-quality aluminum alloy to improve durability and stability. Stainless steel ball bearing concave pulley, polished surface, stable use, no friction jamming, easy installation, rope hole is easy to pass through, double pulley provides better safety.
The climbing pulley breaking strength is 25 KN / 5500 LBS and the net weight is 304g / 0.67 lb. Dimensions are max rope diameter: 13mm/0.51" 4/5000; max cable diameter: 12mm/0.36". Suitable for most outdoor activities.