www.rittenhouse.ca Bruce describes the SOLO 425 backpack sprayer, he also explains why the SOLO 425 DLX is different. The third sprayer that he will be explaining is the Chapin proseries Backpack Sprayer, model 61800. This Chapin Sprayer is designed to provide years of dependable use for a variety of needs. Manufactured from durable high-density polyethylene, the Chapin sprayer will operate at optimum efficiency for years to come.