—  It ensures the tail of the approved stopper knot is sufficiently long

Klein Replacement Tree Gaffs — 2-3/4"

Yes — see the Rescue Figure 8 Descender for a heavier-duty version rated for rescue applications

We're also including The Tree Climber's Companion book in this kit

accessible

PHOSPHO-JET 1 LITER shoulder straps — It ensures the tailArborjet's PHOSPHO jet is a systemic fungicide and plant resistance activator for the suppression of various plant diseases. **Contains 45. 8% Phosphorous Acid 1 Liter treats 20 trees (10" DBH) Effective for: Sudden Oak Death, Anthracnose, Phytophthora, Black Spot, Scab, Fire Blight in Apple, Root Rot in Avocado and Citrus, Canker Blight and many others