The KDS® Job Boss Pro Extra Heavy Duty H-type Utility Knife (1in) has a strong ABS plastic body and comes with one Power Black EVO H-Blade.  This is an excellent, cost-effective choice for contractors on a tight budget.

Solid Replacement Blades:
KDS® Power Black EVO Solid 1in HD Utility Blades (I-SHD10PK)

Snap-Off Replacement Blades:
KDS® Power Black EVO Snap-Off 1in Utility Blades (I-HD5PK/I-HD10PK/I-HD50PK) KDS Heavy-Duty Plastic Utility Knife